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Synthesis and crystal structures of three Schiff bases derived from 3-formyl­acetyl­acetone and benzyl-, tert-butyl- and (S)-methyl­benzyl­amine

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aMartin-Luther-Universität Halle-Wittenberg, Naturwissenschaftliche Fakultät II, Institut für Chemie, D-06099 Halle, Germany
*Correspondence e-mail: kurt.merzweiler@chemie.uni-halle.de

Edited by M. Weil, Vienna University of Technology, Austria (Received 29 May 2023; accepted 4 July 2023; online 11 July 2023)

Treatment of 3-formyl­acetyl­acetone with the amines benzyl­amine, tert-butyl­amine and (S)-methyl­benzyl­amine led to the formation of the corresponding Schiff bases 3-[(benzyl­amino)­methyl­idene]pentane-2,4-dione, C13H15NO2 (1), 3-[(tert-butyl­amino)­methyl­idene]pentan-2,4-dione, C10H17NO2 (2) and 3-{[(S)-benz­yl(meth­yl)amino]­methyl­idene}pentane-2,4-dione, C14H17NO2 (3). The mol­ecules of all three compounds exist as enamine tautomers that contain a nearly planar amino-methyl­ene-pentane-2,4-dione core with a strong intra­molecular N—H⋯O hydrogen bridge. The R group attached to the enamine N atom has no significant influence on the bond lengths and angles of the amino-methyl­ene-pentane-2,4-dione core. The supra­molecular structures in 13 are mainly based on weak C—H⋯O hydrogen bonds.

1. Chemical context

3-Formyl­acetyl­acetone reacts with primary amines RNH2 to give enamines with an amino-methyl­ene-pentane-2,4-dione core. The first reference to this type of Schiff base compound dates back to Claisen, who used eth­oxy­lidene­acetyl­acetone as synthetic alternative to 3-formyl­acetyl­acetone. 3-Amino­methyl­ene-pentane-2,4-dione, which may be regarded as the parent compound, was reported as early as 1893 (Claisen, 1893[Claisen, L. R. (1893). Ber. Dtsch. Chem. Ges. 26, 2729-2735.]), and its crystal structure was reported in 2006 (Gróf et al., 2006[Gróf, M., Milata, V. & Kožíšek, J. (2006a). Acta Cryst. E62, o4464-o4465.]a), almost simultaneously with that of the methyl­amino derivative (Gróf et al., 2006[Gróf, M., Milata, V., Kožíšek, J. & Tokarčík, M. (2006b). Acta Cryst. E62, o4060-o4061.]b). In 1966, Wolf & Jäger. successfully used the deprotonation of 3-amino­methyl­ene-pentane-2,4-dione type Schiff bases to generate β-imino­enolate chelate ligands, with special focus on tetra­dentate salen-type ligands (Wolf & Jäger, 1966[Wolf, L. & Jäger, E.-G. (1966). Z. Anorg. Allg. Chem. 346, 76-91.]). In particular, these salen-type ligands have found broad application in the synthesis of FeII complexes exhibiting spin-crossover effects (Dürrmann et al., 2021[Dürrmann, A., Hörner, G., Wagner, S., Breuning, M. & Weber, B. (2021). Z. Anorg. Allg. Chem. 647, 2088-2097.]). Moreover, the coordination properties of the imino­enolate ligands are conveniently modified by the introduction of additional donor groups. This is easily done by the reaction of 3-formyl­acetyl­acetone with a suitably functionalized amine, e.g. in form of α-amino acids (Hentsch et al., 2014[Hentsch, A., Wagner, C. & Merzweiler, K. (2014). Z. Anorg. Allg. Chem. 640, 339-346.]) or o-di­phenyl­phosphinoaniline (Halz et al., 2021[Halz, J. H., Hentsch, A., Wagner, C. & Merzweiler, K. (2021). Z. Anorg. Allg. Chem. 647, 922-930.]).

In the current communication, we focus on some structural aspects of three derivatives, namely 3-[(benzyl­amino)­methyl­ene]pentane-2,4-dione (1), 3-[(tert-butyl­amino)­methylen]pent­an-2,4-dione (2) and 3-{[(S)-methyl­benzyl­amino]­methyl­en}pentane-2,4-dione (3). Formally, all three compounds can be derived from 3-[(methyl­amino)­methyl­ene]pentane-2,4-dione by partial or complete replacement of the methyl H atoms with other residues (Me, Ph). It can thus be expected that the main structural differences between compounds 13 will arise from conformational aspects regarding the orientation of the CH2Ph, CH(CH3)Ph and C(CH3)3 moieties with respect to the 3-amino­methyl­ene-pentane-2,4-dione core. In order to get some insight into the differences between solid-state and (theoretical) gas phase structures, compounds 13 were also characterized by DFT calculations.

[Scheme 1]

From the synthetic point of view it is worth mentioning that compounds 1 and 2 are also accessible by the eth­oxy­lidene­acetyl­acetone route (Zhou, 1997[Zhou, J.-C. (1997). Magn. Reson. Chem. 35, 432-440.]). Originally, compound 2 was obtained from a formimidoyl­ation of acetyl­acetone with a substituted imidazole (Ito et al., 1974[Ito, Y., Inubushi, Y. & Saegusa, T. (1974). Tetrahedron Lett. 15, 1283-1286.]).

2. Structural commentary

Compounds 1 and 2 crystallize in the monoclinic system, space group P21/c with Z = 4. Compound 3 forms monoclinic crystals in space group P21 with Z = 4. Both independent mol­ecules in the asymmetric unit of 3 exhibit nearly identical bond lengths and angles.

Compounds 13 (Figs. 1[link]–3[link][link]) exist as enamine tautomers that contain nearly planar amino-methyl­ene-pentane-2,4-dione cores. The largest deviation from the least-squares plane through the core atoms C1–C7, O1, O2 and N is found for C1 in compound 2 with 0.3252 (9) Å. The enamine double bonds C3=C6 vary from 1.399 (4) to 1.407 (2) Å and the enamine C6=N bonds are in the range 1.308 (2) to 1.321 (4) Å (Tables 1[link]–3[link][link]). These values are close to those found in the parent compound amino-methyl­ene-pentane-2,4-dione (1.397 and 1.304 Å, respectively; Gróf et al., 2006a[Gróf, M., Milata, V. & Kožíšek, J. (2006a). Acta Cryst. E62, o4464-o4465.]) and in the related NMe derivative (1.405 and 1.309 Å, respectively; Gróf et al., 2006b[Gróf, M., Milata, V., Kožíšek, J. & Tokarčík, M. (2006b). Acta Cryst. E62, o4060-o4061.]). The same holds for the corresponding Schiff bases derived from isomeric o-, m- and p-amino­benzoic acids (Halz et al., 2022[Halz, J. H., Hentsch, A., Wagner, C. & Merzweiler, K. (2022). Acta Cryst. E78, 54-59.]), α-amino acids (Hentsch et al., 2014[Hentsch, A., Wagner, C. & Merzweiler, K. (2014). Z. Anorg. Allg. Chem. 640, 339-346.]) or o-di­phenyl­phosphinoaniline (Halz et al., 2021[Halz, J. H., Hentsch, A., Wagner, C. & Merzweiler, K. (2021). Z. Anorg. Allg. Chem. 647, 922-930.]). In summary, these observations clearly indicate that the R group attached to the enamine N atom has no significant influence on the bond lengths and angles of the amino-methyl­ene-pentane-2,4-dione moiety. This holds also for the characteristic S11(6) type intra­molecular N—H8⋯O1 hydrogen bonds that change only marginally [DA distances between 2.597 (4) and 2.6322 (16) Å; Tables 4[link]–7[link][link]].

Table 1
Selected geometric parameters (Å, °) for 1[link]

C1—C2 1.511 (2) C7—N 1.462 (2)
C2—O1 1.245 (2) C7—C8 1.519 (2)
C2—C3 1.456 (2) C8—C13 1.384 (2)
C3—C6 1.404 (2) C8—C9 1.393 (2)
C3—C4 1.469 (2) C9—C10 1.384 (2)
C4—O2 1.2350 (19) C10—C11 1.379 (3)
C4—C5 1.512 (3) C11—C12 1.388 (3)
C6—N 1.316 (2) C12—C13 1.386 (2)
       
C8—C7—N—C6 −94.4 (2)    

Table 2
Selected geometric parameters (Å, °) for 2[link]

C1—C2 1.5042 (13) C4—O2 1.2287 (12)
C2—O1 1.2419 (12) C4—C5 1.5135 (15)
C2—C3 1.4502 (14) C7—C8 1.5197 (14)
C3—C6 1.4043 (12) C7—C9 1.5235 (14)
C3—C4 1.4578 (13) C7—C10 1.5237 (14)
       
C8—C7—N—C6 −14.03 (14) C10—C7—N—C6 107.27 (11)
C9—C7—N—C6 −134.31 (11)    

Table 3
Selected geometric parameters (Å, °) for 3[link]

C1—C2 1.504 (5) C15—C16 1.510 (5)
C2—O1 1.246 (4) C16—O3 1.236 (4)
C2—C3 1.453 (4) C16—C17 1.455 (4)
C3—C6 1.399 (4) C17—C20 1.396 (4)
C3—C4 1.472 (5) C17—C18 1.468 (4)
C4—O2 1.224 (4) C18—O4 1.228 (4)
C4—C5 1.517 (5) C18—C19 1.518 (5)
C6—N1 1.311 (4) C20—N2 1.321 (4)
C7—N1 1.470 (4) C21—N2 1.463 (4)
C7—C8 1.522 (4) C21—C28 1.524 (5)
C7—C14 1.527 (5) C21—C22 1.534 (4)
       
C8—C7—N1—C6 −119.2 (3) C22—C21—N2—C20 −112.8 (3)
C14—C7—N1—C6 115.5 (4) C28—C21—N2—C20 122.4 (3)

Table 4
Hydrogen-bond geometry (Å, °) for 1[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N—H8⋯O1 0.87 1.97 2.6177 (18) 130
C6—H7⋯O2i 0.94 2.57 3.434 (2) 154
Symmetry code: (i) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Table 5
Hydrogen-bond geometry (Å, °) for 2[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N—H8⋯O1 0.90 (2) 1.90 (2) 2.6322 (16) 136 (2)
C5—H4⋯O1i 0.97 (2) 2.69 (2) 3.630 (2) 163 (2)
C8—H11⋯O2ii 0.98 (2) 2.67 (2) 3.642 (2) 174 (1)
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) [-x+1, -y, -z+1].

Table 6
Hydrogen-bond geometry (Å, °) for 3[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H8⋯O1 0.88 1.94 2.597 (4) 131
N2—H25⋯O3 0.88 1.95 2.603 (4) 130
C14—H15⋯O2i 0.98 2.55 3.532 (5) 175
C14—H17⋯O4 0.98 2.66 3.482 (5) 142
C28—H32⋯O4i 0.98 2.54 3.512 (5) 173
Symmetry code: (i) [x-1, y, z].
[Figure 1]
Figure 1
Mol­ecular structure of 1 showing the labeling scheme. Displacement ellipsoids drawn at the 50% probability level.
[Figure 2]
Figure 2
Mol­ecular structure of 2 showing the labeling scheme. Displacement ellipsoids drawn at the 50% probability level.
[Figure 3]
Figure 3
Mol­ecular structure of 3 showing the labeling scheme. Displacement ellipsoids drawn at the 50% probability level.

Regarding the conformational aspects, 3-[(methyl­amino)­methyl­ene]pentane-2,4-dione may serve as a reference. In this case, the N-bound CH3 group exhibits H—C—N—Cenamine torsion angles of 1.5 (2), −118.4 (2) and 121.6 (2)° (Gróf et al., 2006a[Gróf, M., Milata, V. & Kožíšek, J. (2006a). Acta Cryst. E62, o4464-o4465.]). This indicates a nearly ideal syn-periplanar orientation of one of the hydrogen atoms and anti-periplanar positions for the remaining hydrogen atoms. The formal replacement of one H atom by a phenyl group in the structure of 1 leads to an approximately 26° clockwise rotation of the CH2Ph unit along the N—C7 bond. As a result, the hydrogen atoms are now moved to syn-periplanar and anti-periplanar positions (H9—C7—N—C6 = 27.2°, H10—C7—N—C6 = 144.0°) and the phenyl carbon atom C8 is in an anti-clinal position [C8—C7—N—C6 = −94.4 (2)°]. In the case of the tBu derivative 2, the presence of three equivalent methyl groups leads to a conformation similar to that of the methyl derivative with syn-periplanar orientation of one methyl group [C8—C7—N—C6 = −4.03 (14)°] and an anti-clinal arrangement for the remaining methyl groups [C9—C7—N—C6 = −134.31 (11)°] C10—C7—N—C6 = 107.27 (11)°]. In the structure of 3, both the methyl and the phenyl carbon atoms are moved to anti-clinal positions [C14—C7—N1—C6 = 115.5 (4)°; 122.4 (3)° for the second mol­ecule], C8—C7—N1—C6 = −119.2 (3)°; 112.8 (3)° for second mol­ecule] and the hydrogen atom resides in a nearly ideal syn-periplanar position (H9—C7—N—C6 = −1.47°; 5.16° for the second mol­ecule).

In order to get some insight into how the observed conformations are influenced by crystal packing, the gas phase mol­ecular structures of 13 were optimized by DFT methods using the Gaussian 16 program package (Frisch et al., 2016[Frisch, M. J., Trucks, G. W., Schlegel, H. B., Scuseria, G. E., Robb, M. A., Cheeseman, J. R., Scalmani, G., Barone, V., Petersson, G. A., Nakatsuji, H., Li, X., Caricato, M., Marenich, A. V., Bloino, J., Janesko, B. G., Gomperts, R., Mennucci, B., Hratchian, H. P., Ortiz, J. V., Izmaylov, A. F., Sonnenberg, J. L., Williams-Young, D., Ding, F., Lipparini, F., Egidi, F., Goings, J., Peng, B., Petrone, A., Henderson, T., Ranasinghe, D., Zakrzewski, V. G., Gao, J., Rega, N., Zheng, G., Liang, W., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Throssell, K., Montgomery, J. A. Jr, Peralta, J. E., Ogliaro, F., Bearpark, M. J., Heyd, J. J., Brothers, E. N., Kudin, K. N., Staroverov, V. N., Keith, T. A., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A. P., Burant, J. C., Iyengar, S. S., Tomasi, J., Cossi, M., Millam, J. M., Klene, M., Adamo, C., Cammi, R., Ochterski, J. W., Martin, R. L., Morokuma, K., Farkas, O., Foresman, J. B. & Fox, D. J. (2016). Gaussian 16. Gaussian Inc. Wallingford CT.]) at the B3LYP/TZVP/GD3BJ level of theory (Becke, 1993[Becke, A. D. (1993). J. Chem. Phys. 98, 5648-5652.]) with the implemented def2-TZVP basis set (Weigand & Ahlrichs, 2005[Weigend, F. & Ahlrichs, R. (2005). Phys. Chem. Chem. Phys. 7, 3297-3305.]) and dispersion correction GD3BJ (Grimme et al., 2011[Grimme, S., Ehrlich, S. & Goerigk, L. (2011). J. Comput. Chem. 32, 1456-1465.]).

Bond lengths and angles of the calculated structures are in good agreement with the experimetal data. In Fig. 4[link], an overlay of the experimetal (blue) and the calculated structures (red) is shown. Obviously, the planar amino-methyl­ene-pentane-2,4-dione cores fit very well and most of the differences between experimental and theoretical structures are due to the conformations of the organyl groups attached to the enamine nitro­gen atom.

[Figure 4]
Figure 4
Mol­ecule structure overlay of the experimental (blue) and the calculated structures (red) in 1 (a), 2 (b) and 3 (c), created with Mercury (Macrae et al., 2020[Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226-235.]).

Table 7[link] represents a comparison of experimental and calculated torsion angles at the C7—N bond. In the case of compounds 1 and 2, there is only a moderate increase of the torsion angles with respect to the theoretical values. Additionally, compound 1 exhibits a small change in the orientation of the phenyl group (Fig. 4[link]a). In the case of compound 3, the conformational effects are more pronounced and the torsion angles are increased by around 73°. Moreover, the orientation of the phenyl group is also affected (Fig. 4[link]c).

Table 7
Comparison of torsion angles in the crystal structures of 13 and from theoretical DFT calculations

Compound Torsion angle Crystal structure determination DFT calculation
1 C8—C7—N—C6 –94.4 (1) –107.8
2 C8—C7—N—C6 −14.03 (14) 0.0
  C9—C7—N—C6 –134.31 (11) –120.8
  C10—C7—N—C6 107.27 (11) 120.8
3 C8—C7—N1—C6 –119.2 (4); −112.8 (3)* –43.3
  C14—C7—N1—C6 115.5 (4); 122.4 (3)* –167.3
*Values for the comparable bond in the second mol­ecule.

3. Supra­molecular features

In order to identify the most significant inter­molecular inter­actions, Hirshfeld surface analyses (Spackman et al., 2009[Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19-32.]) for compounds 13 (Figs. 5[link]–7[link][link]) were carried out with CrystalExplorer (Spackman et al., 2021[Spackman, P. R., Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Jayatilaka, D. & Spackman, M. A. (2021). J. Appl. Cryst. 54, 1006-1011.]).

[Figure 5]
Figure 5
View of the Hirshfeld surface of 1 mapped over dnorm in the range −0.712 to 0.973 au, showing inter­molecular hydrogen bonds as green dashed lines.
[Figure 6]
Figure 6
View of the Hirshfeld surface of 2 mapped over dnorm in the range −0.712 to 0.973 au, showing inter­molecular hydrogen bonds as green dashed lines.
[Figure 7]
Figure 7
View of the Hirshfeld surface of mol­ecule 1 of compound 3 mapped over dnorm in the range −0.712 to 0.973 au, showing inter­molecular hydrogen bonds as green dashed lines.

In the case of compound 1 there is a C11 (5) type C—H⋯O hydrogen bridge between the enamine CH group (C6—H7) and the acetyl O atom (O2) of of a neighboring mol­ecule (Table 4[link], Fig. 8[link]). This leads to helical chains that propagate in the direction of the c axis. Moreover, the packing of the helices is supported by weak ππ inter­actions [3.8747 (12) Å between the centroids of the phenyl groups, 3.79 Å between C3 of the (amino)­methyl­ene-pentane-2,4-dione unit and the centroid of the phenyl ring and 3.42 Å between neighboring (amino)­methyl­ene-pentane-2,4-dione units]. As a result, ribbons extending parallel to [001] are formed, Figs. 9[link], 10[link].

[Figure 8]
Figure 8
Section of the crystal structure of 1 showing the hydrogen bond. [Symmetry codes: (i) x, [{3\over 2}] − y, −[{1\over 2}] + z; (ii) x, [{3\over 2}] − y, [{1\over 2}] + z.]
[Figure 9]
Figure 9
Stacking of mol­ecules in 1 resulting in a layered arrangement parallel to (110). Bold dashed lines show the closest contacts with neighboring phenyl and pentane-2,4-dione planes.
[Figure 10]
Figure 10
Helical chains of 1 stabilized by hydrogen bonds (thin dashed lines) and ππ inter­actions.

The Hirshfeld plot of compound 2 reveals that each mol­ecule is involved in four C—H⋯O hydrogen bridges between t-butyl groups and acetyl oxygen atoms of neighboring mol­ecules (Fig. 6[link]). Formally, this can be considered as a formation of dimers based on the complementary hydrogen bridges C8—H11⋯O2′ to give a R22(16) motif. Additionally, the dimers are catenated by C11(6) type hydrogen bridges along the a axis (Table 5[link], Fig. 11[link]).

[Figure 11]
Figure 11
Stacking of the mol­ecules in 2 along the [001] direction.

Compound 3 exhibits two major types of inter­actions that are based on C—H⋯O hydrogen bridges (Table 6[link]) and C—H⋯π contacts with an H⋯Cg(phen­yl) distance of 2.68 Å. The C—H⋯O hydrogen bridges are formed between methyl and phenyl groups of the methyl­benzyl residue as donors and acetyl oxygen atoms of neighboring mol­ecules as acceptors (Fig. 12[link]). In the case of the C—H⋯π inter­action, the benzyl CH fragment and a neighboring phenyl group are involved (Fig. 13[link], for mol­ecule 1).

[Figure 12]
Figure 12
Section of the crystal structure of 3 showing the hydrogen bonds (dashed lines). [Symmetry codes: (i) 1 − x, −[{1\over 2}] + y, −z; (ii) 1 − x, y, z; (iii) −x, [{1\over 2}] + y, 1 − z; (iv) 1 − x, [{1\over 2}] + y, −z; (v) 1 + x, y, z; (vi) −x, −[{1\over 2}] + y, 1 − z; (vii) 1 + x, y z.]
[Figure 13]
Figure 13
Section of the crystal structure of 3 showing the C—H⋯π inter­action (thick dashed line).

A comparison of the calculated gas phase structures and the experimentally determined structures reveals that the effect of crystal packing is only marginal for compounds 1 and 2, i.e. only minor adjustments of the mol­ecular conformations are required for optimum inter­molecular inter­actions. In contrast to these compounds, 3 requires a stronger mol­ecular reorganization in the solid state and presumably this is in particular due to C—H⋯π inter­actions.

4. Database survey

Currently the Cambridge Structural Database (CSD, version 2020.3, Groom et al., 2016) contains 22 entries for Schiff bases with amino-methyl­ene-pentane-2,4-dione cores. In all cases, enamine tautomers are observed.

5. Synthesis and crystallization

3-Formyl­acetyl­acetone (3.00 g, 23.4 mmol) and the corresponding amine [1.76 g of benzyl­amine for 1, 2.57 g of tert-butyl­amine for 2 and 2.91 g of (S)-methyl-benzyl­amine for 3, 24.0 mmol] were dissolved in methanol (50 ml) and heated under reflux for one h. After removal of the volatiles in vacuo, the residue was washed twice with cold n-pentane and afterwards dried in vacuo.

Yield: 2.5 g (77%) for 1, 2.7g (85%) for 2 and 4.3 g (77%) for 3 based on 3-formyl­acetyl­acetone. Compounds 13 were obtained as yellow air-stable powders that are soluble in polar solvents such as methanol or CHCl3 and less soluble in toluene or n-hexane.

Crystals suitable for single-crystal X-ray diffraction were obtained by slow evaporation of the solvent from solutions in methanol (compounds 1 and 3) or diethyl ether (compound 2).

Compound 1: m.p. = 368 K. Elemental Analysis for C13H15NO2: Calculated: C 77.72, H 7.36, N 6.06%. Found: C 77.22, H 7.22, N 5.90%.

IR: 2971 (m), 1618 (vs), 1570 (vs), 1494 (m), 1446 (w), 1390 (s), 1349 (m), 1308 (s), 1242 (s), 1201 (w), 1119 (m), 1070 (w), 1023 (m), 975 (s), 927 (m), 816 (s), 755 (s), 705 (s), 620 (s), 552 (m), 508 (m), 444 (w) cm−1.

1H-NMR (CDCl3, 400 MHz) δ = 2.22 (s, 3 H, CO—CH3), 2.47 (s, 3 H, CO—CH3), 4.51 (d 3J = 5.9 Hz, 2 H, CH2), 7.22–7.38 (m, 5 H, CHaromatic), 7.77 (d, 3J = 13,1 Hz, 1 H, CH), 11.28 (s, 1 H, NH) ppm,

13C-NMR (CDCl3, 100 MHz) δ = 27.2 (–CH3), 31.8 (–CH3), 53.7 (–CH2), 111.9 [C(O)—C—C(O)], 127.2 (CHaromatic), 128.3 (CHaromatic), 129.0 (CHaromatic), 135.9 (CHaromatic), 159.6, (CH—NH), 194.2 (CO), 200.3 (CO) ppm.

Compound 2: m.p. = 355 K. Elemental Analysis for C10H17NO2: Calculated: C 65.54, H 9.35, N 7.64%. Found: C 64.78, H 9.26, N 7.33%.

IR: 2970 (m), 1649 (w), 1608 (m), 1578 (vs), 1470 (w), 1400 (m), 1382 (m), 1321 (m), 1281 (s), 1240 (m), 1205 (m), 1025 (m), 990 (m), 975 (s), 944 (w), 928 (m), 827 (s), 646 (w), 626 (s), 567 (s), 500 (w), 474 (w), 413 (w), 333 (m), 305 (w), 272 (w) cm−1.

1H-NMR (CDCl3, 400 MHz) δ = 1.31 [s, 9 H, C(CH3)], 2.25 (s, 3 H, CH3), 2.45 (s, 3 H, CH3), 7.85 (d, 3J = 13.7 Hz, 1 H, CH), 11.39 (s, 1 H, NH) ppm.

13C-NMR (CDCl3, 100 MHz) δ = 27.4 (–CH3), 29.8 [–C(CH3)3], 31.8 (–CH3), 53.6 [–C(CH3)3], 111.2 [C(O)—C–-C(O)], 155.2, (CH—NH), 194.2 (CO), 199.8 (CO) ppm.

Compound 3: m.p. = 335 K. Elemental Analysis for C14H17NO2: Calculated: C 72.70, H 7.41, N 6.06%. Found: C 72.22, H 7.22, N 5.90%.

IR: 2971 (m), 1618 (vs), 1570 (vs), 1494 (m), 1446 (w), 1390 (s), 1349 (m), 1308 (s), 1242 (s), 1201 (w), 1119 (m), 1070 (w), 1023 (m), 975 (s), 927 (m), 816 (s), 755 (s), 705 (s), 620 (s), 552 (m), 508 (m), 444 (w) cm−1.

1H-NMR (CDCl3, 400 MHz) δ = 1.62 (d, 3 H, NCCH3), 2.15 (s, 3 H,CH3), 2.47 (s, 3 H, (CH3), 4.56 (dq, 3J = 6.9 Hz, 3J = 7.0 Hz, 1 H, CH), 7.25–7.37 (m, 5 H, CHaromatic), 7.72 (d, 3J = 6,9 Hz, 1 H, CH), 11.40 (s, 1 H, NH) ppm.

13C-NMR (CDCl3, 100 MHz) δ = 23.4 (NCCH3), 27.2 (–CH3),31.9 (–CH3), 59.1 (NCCH3), 111.7 [C(O)—C–-C(O)], 126.0 (CHaromatic), 128.2 (CHaromatic), 129.1 (CHaromatic), 141.7 (CHaromatic), 158.2 (CH—NH), 194.3 (CO,) 200.3 (CO) ppm.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 8[link]. Hydrogen atoms were positioned geometrically (C—H = 0.95–0.98 Å) and refined as riding, with Uiso(H) = 1.2Ueq(C) for CH and NH hydrogen atoms and Uiso(H) = 1.5Ueq(C) for CH3 hydrogen atoms. The investigated crystal of 3 was twinned by non-merohedry and treated as a two-domain crystal with a refined BASF factor of 0.1151.

Table 8
Experimental details

  1 2 3
Crystal data
Chemical formula C13H15NO2 C10H17NO2 C14H17NO2
Mr 217.26 183.24 231.28
Crystal system, space group Monoclinic, P21/c Monoclinic, P21/c Monoclinic, P21
Temperature (K) 213 170 170
a, b, c (Å) 11.7356 (14), 9.2401 (8), 11.3970 (14) 9.8226 (7), 9.8323 (6), 11.2700 (8) 10.0459 (9), 8.1011 (5), 15.7052 (13)
β (°) 113.148 (14) 108.171 (5) 103.372 (7)
V3) 1136.4 (2) 1034.16 (12) 1243.48 (17)
Z 4 4 4
Radiation type Mo Kα Mo Kα Mo Kα
μ (mm−1) 0.09 0.08 0.08
Crystal size (mm) 0.33 × 0.15 × 0.12 0.32 × 0.28 × 0.21 0.44 × 0.21 × 0.14
 
Data collection
Diffractometer Stoe IPDS 2 Stoe IPDS 2 Stoe IPDS 2T
No. of measured, independent and observed [I > 2σ(I)] reflections 7396, 2159, 1414 7337, 2774, 2126 11343, 11343, 9181
Rint 0.078 0.033 0.042
(sin θ/λ)max−1) 0.616 0.685 0.688
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.097, 0.94 0.036, 0.104, 1.03 0.048, 0.131, 1.05
No. of reflections 2159 2774 11343
No. of parameters 147 123 315
No. of restraints 0 0 1
H-atom treatment H-atom parameters constrained H-atom parameters constrained H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.18, −0.17 0.30, −0.14 0.27, −0.28
Absolute structure Classical Flack method preferred over Parsons because s.u. lower.
Absolute structure parameter 2.9 (7)
Computer programs: X-AREA WinXpose (Stoe, 2016[Stoe (2016). X-AREA and X-AREA WinXpose. Stoe & Cie, Darmstadt, Germany.]), X-AREA Recipe (Stoe, 2015[Stoe (2015). X-AREA Recipe. Stoe & Cie, Darmstadt, Germany.]), X-AREA (Stoe, 2016[Stoe (2016). X-AREA and X-AREA WinXpose. Stoe & Cie, Darmstadt, Germany.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL (Sheldrick, 2015b[Sheldrick, G. M. (2015a). Acta Cryst. C71, 3-8.]), DIAMOND (Brandenburg, 2019[Brandenburg, K. (2019). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Supporting information


Computing details top

For all structures, data collection: X-AREA WinXpose (Stoe, 2016); cell refinement: X-AREA Recipe (Stoe, 2015); data reduction: X-AREA (Stoe, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 2019); software used to prepare material for publication: Olex2 (Dolomanov et al., 2009).

3-[(Benzylamino)methylidene]pentane-2,4-dione (1) top
Crystal data top
C13H15NO2F(000) = 464
Mr = 217.26Dx = 1.270 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 11.7356 (14) ÅCell parameters from 7396 reflections
b = 9.2401 (8) Åθ = 2.9–26.0°
c = 11.3970 (14) ŵ = 0.09 mm1
β = 113.148 (14)°T = 213 K
V = 1136.4 (2) Å3Block, clear yellow
Z = 40.33 × 0.15 × 0.12 mm
Data collection top
STOE IPDS 2
diffractometer
Rint = 0.078
rotation scansθmax = 26.0°, θmin = 2.9°
7396 measured reflectionsh = 1313
2159 independent reflectionsk = 1111
1414 reflections with I > 2σ(I)l = 1313
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.097 w = 1/[σ2(Fo2) + (0.0469P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.94(Δ/σ)max < 0.001
2159 reflectionsΔρmax = 0.18 e Å3
147 parametersΔρmin = 0.17 e Å3
0 restraints
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.29032 (19)0.4837 (2)1.16212 (15)0.0391 (5)
H10.23340.41361.17240.059*
H20.27180.57901.18580.059*
H30.37470.45741.21650.059*
C20.27629 (16)0.48567 (19)1.02452 (14)0.0284 (4)
C30.34838 (15)0.58355 (17)0.98050 (14)0.0239 (4)
C40.43034 (16)0.69625 (18)1.06114 (14)0.0265 (4)
C50.4992 (2)0.7943 (2)1.00520 (17)0.0404 (5)
H40.44050.84130.92940.061*
H50.55710.73740.98270.061*
H60.54420.86701.06760.061*
C60.34363 (15)0.56658 (17)0.85623 (14)0.0244 (4)
H70.39490.62770.83240.029*
C70.27877 (17)0.45955 (19)0.64354 (14)0.0297 (4)
H90.26770.35730.61860.036*
H100.36100.48900.64920.036*
C80.18161 (16)0.54814 (17)0.53978 (14)0.0235 (4)
C90.15894 (17)0.51739 (19)0.41290 (15)0.0307 (4)
H110.20170.44120.39350.037*
C100.07407 (18)0.5979 (2)0.31512 (15)0.0353 (5)
H120.05880.57540.22980.042*
C110.01179 (18)0.7110 (2)0.34239 (16)0.0363 (5)
H130.04440.76700.27600.044*
C120.03245 (19)0.7418 (2)0.46829 (17)0.0394 (5)
H140.01080.81780.48730.047*
C130.11704 (17)0.66035 (19)0.56594 (16)0.0329 (4)
H150.13070.68160.65110.040*
N0.27486 (14)0.47394 (15)0.76962 (11)0.0290 (4)
H80.22450.41840.78840.035*
O10.20370 (13)0.39610 (15)0.95112 (11)0.0439 (4)
O20.44589 (13)0.71536 (15)1.17367 (10)0.0418 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0467 (13)0.0475 (12)0.0277 (9)0.0032 (10)0.0196 (9)0.0032 (8)
C20.0266 (10)0.0345 (10)0.0231 (8)0.0034 (8)0.0087 (7)0.0020 (7)
C30.0247 (10)0.0277 (9)0.0173 (7)0.0044 (7)0.0063 (7)0.0020 (6)
C40.0271 (10)0.0277 (9)0.0220 (8)0.0066 (7)0.0068 (7)0.0002 (7)
C50.0527 (14)0.0324 (10)0.0329 (9)0.0132 (9)0.0135 (9)0.0055 (8)
C60.0246 (10)0.0226 (8)0.0234 (8)0.0020 (7)0.0066 (7)0.0039 (7)
C70.0372 (11)0.0319 (9)0.0194 (8)0.0020 (8)0.0104 (7)0.0029 (7)
C80.0253 (10)0.0253 (8)0.0197 (8)0.0045 (7)0.0087 (7)0.0024 (6)
C90.0364 (11)0.0335 (10)0.0230 (8)0.0026 (8)0.0125 (7)0.0022 (7)
C100.0423 (12)0.0435 (11)0.0186 (8)0.0020 (9)0.0105 (8)0.0006 (8)
C110.0345 (12)0.0358 (11)0.0311 (9)0.0005 (8)0.0049 (8)0.0089 (8)
C120.0378 (12)0.0376 (11)0.0389 (10)0.0106 (9)0.0107 (9)0.0035 (8)
C130.0345 (11)0.0383 (10)0.0239 (8)0.0019 (8)0.0092 (8)0.0076 (7)
N0.0351 (9)0.0317 (8)0.0184 (7)0.0059 (7)0.0087 (6)0.0007 (6)
O10.0468 (9)0.0559 (9)0.0285 (7)0.0222 (7)0.0145 (6)0.0036 (6)
O20.0464 (9)0.0535 (8)0.0232 (6)0.0082 (7)0.0111 (6)0.0115 (6)
Geometric parameters (Å, º) top
C1—C21.511 (2)C7—C81.519 (2)
C1—H10.9700C7—H90.9800
C1—H20.9700C7—H100.9800
C1—H30.9700C8—C131.384 (2)
C2—O11.245 (2)C8—C91.393 (2)
C2—C31.456 (2)C9—C101.384 (2)
C3—C61.404 (2)C9—H110.9400
C3—C41.469 (2)C10—C111.379 (3)
C4—O21.2350 (19)C10—H120.9400
C4—C51.512 (3)C11—C121.388 (3)
C5—H40.9700C11—H130.9400
C5—H50.9700C12—C131.386 (2)
C5—H60.9700C12—H140.9400
C6—N1.316 (2)C13—H150.9400
C6—H70.9400N—H80.8700
C7—N1.462 (2)
C2—C1—H1109.5C8—C7—H9108.7
C2—C1—H2109.5N—C7—H10108.7
H1—C1—H2109.5C8—C7—H10108.7
C2—C1—H3109.5H9—C7—H10107.6
H1—C1—H3109.5C13—C8—C9118.63 (16)
H2—C1—H3109.5C13—C8—C7122.88 (14)
O1—C2—C3121.22 (14)C9—C8—C7118.47 (15)
O1—C2—C1117.12 (16)C10—C9—C8120.64 (17)
C3—C2—C1121.60 (15)C10—C9—H11119.7
C6—C3—C2118.70 (15)C8—C9—H11119.7
C6—C3—C4117.82 (15)C11—C10—C9120.23 (16)
C2—C3—C4123.44 (14)C11—C10—H12119.9
O2—C4—C3122.95 (16)C9—C10—H12119.9
O2—C4—C5117.85 (16)C10—C11—C12119.73 (17)
C3—C4—C5119.20 (14)C10—C11—H13120.1
C4—C5—H4109.5C12—C11—H13120.1
C4—C5—H5109.5C13—C12—C11119.84 (18)
H4—C5—H5109.5C13—C12—H14120.1
C4—C5—H6109.5C11—C12—H14120.1
H4—C5—H6109.5C8—C13—C12120.91 (16)
H5—C5—H6109.5C8—C13—H15119.5
N—C6—C3126.77 (16)C12—C13—H15119.5
N—C6—H7116.6C6—N—C7123.33 (16)
C3—C6—H7116.6C6—N—H8118.3
N—C7—C8114.34 (15)C7—N—H8118.3
N—C7—H9108.7
O1—C2—C3—C65.9 (2)N—C7—C8—C9165.58 (16)
C1—C2—C3—C6171.41 (17)C13—C8—C9—C100.3 (3)
O1—C2—C3—C4176.69 (17)C7—C8—C9—C10178.03 (17)
C1—C2—C3—C46.0 (3)C8—C9—C10—C110.8 (3)
C6—C3—C4—O2176.37 (17)C9—C10—C11—C121.5 (3)
C2—C3—C4—O21.1 (3)C10—C11—C12—C131.1 (3)
C6—C3—C4—C53.8 (2)C9—C8—C13—C120.7 (3)
C2—C3—C4—C5178.77 (16)C7—C8—C13—C12177.57 (18)
C2—C3—C6—N3.6 (3)C11—C12—C13—C80.0 (3)
C4—C3—C6—N178.82 (15)C3—C6—N—C7177.67 (16)
N—C7—C8—C1316.1 (2)C8—C7—N—C694.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N—H8···O10.871.972.6177 (18)130
C6—H7···O2i0.942.573.434 (2)154
Symmetry code: (i) x, y+3/2, z1/2.
3-[(tert-Butylamino)methylidene]pentan-2,4-dione (2) top
Crystal data top
C10H17NO2F(000) = 400
Mr = 183.24Dx = 1.177 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 9.8226 (7) ÅCell parameters from 2011 reflections
b = 9.8323 (6) Åθ = 3.7–29.5°
c = 11.2700 (8) ŵ = 0.08 mm1
β = 108.171 (5)°T = 170 K
V = 1034.16 (12) Å3Block, colourless
Z = 40.32 × 0.28 × 0.21 mm
Data collection top
STOE IPDS 2
diffractometer
Rint = 0.033
rotation scansθmax = 29.1°, θmin = 2.8°
7337 measured reflectionsh = 1313
2774 independent reflectionsk = 1313
2126 reflections with I > 2σ(I)l = 1115
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.036H-atom parameters constrained
wR(F2) = 0.104 w = 1/[σ2(Fo2) + (0.0562P)2 + 0.1178P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
2774 reflectionsΔρmax = 0.30 e Å3
123 parametersΔρmin = 0.14 e Å3
0 restraints
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.83575 (10)0.46662 (12)0.88153 (11)0.0344 (2)
H10.86320.48920.97060.052*
H20.88230.52990.83920.052*
H30.86600.37350.87150.052*
C20.67575 (9)0.47771 (10)0.82522 (10)0.0268 (2)
C30.60104 (9)0.41294 (10)0.70726 (9)0.0247 (2)
C40.67422 (10)0.36658 (10)0.62027 (10)0.0274 (2)
C50.59161 (12)0.28835 (12)0.50456 (10)0.0351 (2)
H40.51540.34600.45160.053*
H50.54930.20700.52900.053*
H60.65670.26140.45820.053*
C60.45217 (10)0.39420 (10)0.67456 (9)0.0245 (2)
H70.40750.34450.60030.029*
C70.21415 (9)0.41512 (10)0.71095 (9)0.0242 (2)
C80.14674 (10)0.35776 (12)0.58053 (9)0.0305 (2)
H90.19010.26940.57400.046*
H100.16320.42060.51890.046*
H110.04350.34630.56470.046*
C90.14777 (11)0.55234 (11)0.72323 (12)0.0355 (2)
H120.04490.54090.70970.053*
H130.16220.61540.66090.053*
H140.19350.58910.80710.053*
C100.19622 (11)0.31624 (12)0.80911 (10)0.0324 (2)
H150.09400.30270.79730.049*
H160.24280.35350.89260.049*
H170.24030.22890.80060.049*
N0.36968 (8)0.43920 (9)0.73734 (8)0.02652 (19)
H80.41150.48980.80300.032*
O10.60963 (7)0.53863 (9)0.88675 (8)0.0377 (2)
O20.80125 (8)0.39082 (10)0.63547 (8)0.0414 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0207 (4)0.0420 (6)0.0379 (6)0.0005 (4)0.0056 (4)0.0040 (5)
C20.0207 (4)0.0270 (5)0.0328 (5)0.0015 (3)0.0084 (4)0.0005 (4)
C30.0202 (4)0.0253 (4)0.0296 (5)0.0003 (3)0.0092 (3)0.0014 (4)
C40.0250 (4)0.0272 (5)0.0326 (5)0.0005 (4)0.0126 (4)0.0039 (4)
C50.0353 (5)0.0404 (6)0.0342 (6)0.0024 (4)0.0174 (4)0.0044 (4)
C60.0217 (4)0.0265 (4)0.0255 (4)0.0005 (3)0.0078 (3)0.0008 (4)
C70.0172 (4)0.0296 (4)0.0259 (5)0.0008 (3)0.0068 (3)0.0009 (4)
C80.0230 (4)0.0421 (6)0.0250 (5)0.0027 (4)0.0056 (4)0.0015 (4)
C90.0263 (5)0.0335 (5)0.0477 (7)0.0026 (4)0.0131 (4)0.0034 (5)
C100.0310 (5)0.0387 (6)0.0288 (5)0.0018 (4)0.0109 (4)0.0020 (4)
N0.0177 (3)0.0336 (4)0.0279 (4)0.0015 (3)0.0065 (3)0.0055 (3)
O10.0239 (3)0.0462 (5)0.0420 (5)0.0017 (3)0.0089 (3)0.0172 (4)
O20.0270 (4)0.0555 (5)0.0479 (5)0.0069 (3)0.0207 (3)0.0060 (4)
Geometric parameters (Å, º) top
C1—C21.5042 (13)C7—N1.4815 (11)
C1—H10.9800C7—C81.5197 (14)
C1—H20.9800C7—C91.5235 (14)
C1—H30.9800C7—C101.5237 (14)
C2—O11.2419 (12)C8—H90.9800
C2—C31.4502 (14)C8—H100.9800
C3—C61.4043 (12)C8—H110.9800
C3—C41.4578 (13)C9—H120.9800
C4—O21.2287 (12)C9—H130.9800
C4—C51.5135 (15)C9—H140.9800
C5—H40.9800C10—H150.9800
C5—H50.9800C10—H160.9800
C5—H60.9800C10—H170.9800
C6—N1.3079 (12)N—H80.8800
C6—H70.9500
C2—C1—H1109.5C8—C7—C9110.29 (8)
C2—C1—H2109.5N—C7—C10107.56 (8)
H1—C1—H2109.5C8—C7—C10110.56 (8)
C2—C1—H3109.5C9—C7—C10110.45 (8)
H1—C1—H3109.5C7—C8—H9109.5
H2—C1—H3109.5C7—C8—H10109.5
O1—C2—C3121.36 (8)H9—C8—H10109.5
O1—C2—C1117.32 (9)C7—C8—H11109.5
C3—C2—C1121.22 (8)H9—C8—H11109.5
C6—C3—C2119.08 (8)H10—C8—H11109.5
C6—C3—C4118.29 (9)C7—C9—H12109.5
C2—C3—C4122.63 (8)C7—C9—H13109.5
O2—C4—C3122.54 (10)H12—C9—H13109.5
O2—C4—C5117.84 (9)C7—C9—H14109.5
C3—C4—C5119.61 (8)H12—C9—H14109.5
C4—C5—H4109.5H13—C9—H14109.5
C4—C5—H5109.5C7—C10—H15109.5
H4—C5—H5109.5C7—C10—H16109.5
C4—C5—H6109.5H15—C10—H16109.5
H4—C5—H6109.5C7—C10—H17109.5
H5—C5—H6109.5H15—C10—H17109.5
N—C6—C3125.72 (9)H16—C10—H17109.5
N—C6—H7117.1C6—N—C7127.69 (8)
C3—C6—H7117.1C6—N—H8116.2
N—C7—C8111.38 (8)C7—N—H8116.2
N—C7—C9106.50 (8)
O1—C2—C3—C613.30 (15)C2—C3—C4—C5174.41 (9)
C1—C2—C3—C6163.02 (9)C2—C3—C6—N5.34 (15)
O1—C2—C3—C4166.44 (10)C4—C3—C6—N174.40 (9)
C1—C2—C3—C417.25 (15)C3—C6—N—C7175.98 (9)
C6—C3—C4—O2172.63 (10)C8—C7—N—C614.03 (14)
C2—C3—C4—O27.11 (15)C9—C7—N—C6134.31 (11)
C6—C3—C4—C55.85 (14)C10—C7—N—C6107.27 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N—H8···O10.90 (2)1.90 (2)2.6322 (16)136 (2)
C5—H4···O1i0.97 (2)2.69 (2)3.630 (2)163 (2)
C8—H11···O2ii0.98 (2)2.67 (2)3.642 (2)174 (1)
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+1, y, z+1.
3-{[(S)-Benzyl(methyl)amino]methylidene}pentane-2,4-dione (3) top
Crystal data top
C14H17NO2F(000) = 496
Mr = 231.28Dx = 1.235 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
a = 10.0459 (9) ÅCell parameters from 17500 reflections
b = 8.1011 (5) Åθ = 2.5–29.7°
c = 15.7052 (13) ŵ = 0.08 mm1
β = 103.372 (7)°T = 170 K
V = 1243.48 (17) Å3Block, colourless
Z = 40.44 × 0.21 × 0.14 mm
Data collection top
STOE IPDS 2T
diffractometer
Rint = 0.042
rotation scansθmax = 29.3°, θmin = 2.7°
11343 measured reflectionsh = 1313
11343 independent reflectionsk = 1111
9181 reflections with I > 2σ(I)l = 2121
Refinement top
Refinement on F2H-atom parameters constrained
Least-squares matrix: full w = 1/[σ2(Fo2) + (0.059P)2 + 0.3675P]
where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.048(Δ/σ)max < 0.001
wR(F2) = 0.131Δρmax = 0.27 e Å3
S = 1.05Δρmin = 0.28 e Å3
11343 reflectionsExtinction correction: SHELXL-2018/3 (Sheldrick 2014, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
315 parametersExtinction coefficient: 0.044 (6)
1 restraintAbsolute structure: Classical Flack method preferred over Parsons because s.u. lower.
Primary atom site location: iterativeAbsolute structure parameter: 2.9 (7)
Hydrogen site location: inferred from neighbouring sites
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refined as a 2-component twin.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C11.1723 (4)0.7494 (5)0.1031 (3)0.0494 (10)
H11.22970.72430.16100.074*
H21.17120.86890.09320.074*
H31.20930.69370.05810.074*
C21.0289 (3)0.6899 (4)0.0981 (2)0.0307 (6)
C30.9990 (3)0.5183 (4)0.1133 (2)0.0300 (6)
C41.1060 (4)0.3913 (4)0.1369 (2)0.0364 (7)
C51.0664 (4)0.2163 (5)0.1548 (3)0.0455 (9)
H41.14920.15190.17880.068*
H51.01610.16550.10020.068*
H61.00830.21830.19710.068*
C60.8627 (3)0.4704 (4)0.1047 (2)0.0309 (6)
H70.84650.35690.11370.037*
C70.6134 (3)0.5100 (4)0.0761 (2)0.0315 (6)
H90.61580.38790.08560.038*
C80.5280 (3)0.5433 (4)0.0157 (2)0.0289 (6)
C90.5840 (3)0.6073 (4)0.0821 (2)0.0335 (7)
H100.67870.63360.06980.040*
C100.5044 (4)0.6331 (5)0.1654 (2)0.0373 (7)
H110.54460.67740.20960.045*
C110.3657 (4)0.5946 (5)0.1849 (2)0.0379 (7)
H120.31090.61160.24210.045*
C120.3084 (3)0.5308 (4)0.1193 (2)0.0349 (7)
H130.21380.50400.13190.042*
C130.3882 (3)0.5062 (4)0.0357 (2)0.0310 (6)
H140.34750.46350.00850.037*
C140.5532 (4)0.5888 (5)0.1472 (2)0.0408 (8)
H150.46050.54630.14290.061*
H160.54960.70890.13940.061*
H170.61080.56190.20490.061*
N10.7550 (3)0.5668 (3)0.08533 (19)0.0329 (6)
H80.76840.67240.07730.039*
O10.9351 (3)0.7936 (3)0.07897 (18)0.0389 (6)
O21.2273 (3)0.4204 (4)0.1427 (2)0.0560 (8)
C150.5900 (4)0.2575 (5)0.4013 (3)0.0407 (8)
H180.59560.13690.40630.061*
H190.65390.30750.45130.061*
H200.61380.29210.34690.061*
C160.4461 (3)0.3127 (4)0.4004 (2)0.0326 (7)
C170.4062 (3)0.4854 (4)0.3894 (2)0.0297 (6)
C180.4988 (3)0.6153 (4)0.3729 (2)0.0327 (7)
C190.4459 (4)0.7895 (5)0.3518 (3)0.0454 (9)
H210.43510.84390.40550.068*
H220.35720.78540.30960.068*
H230.51110.85180.32660.068*
C200.2753 (3)0.5311 (4)0.3967 (2)0.0302 (6)
H240.25350.64520.39090.036*
C210.0473 (3)0.4873 (4)0.4252 (2)0.0316 (6)
H260.04240.60970.41680.038*
C220.0360 (3)0.4507 (4)0.5191 (2)0.0280 (6)
C230.1422 (3)0.3812 (4)0.5812 (2)0.0323 (6)
H270.22490.35250.56540.039*
C240.1294 (4)0.3531 (4)0.6661 (2)0.0367 (7)
H280.20270.30400.70760.044*
C250.0096 (4)0.3967 (4)0.6906 (2)0.0364 (7)
H290.00110.37900.74890.044*
C260.0973 (3)0.4662 (4)0.6291 (2)0.0332 (7)
H300.17960.49550.64530.040*
C270.0847 (3)0.4932 (4)0.5438 (2)0.0297 (6)
H310.15860.54080.50210.036*
C280.0694 (4)0.4104 (5)0.3571 (2)0.0371 (7)
H320.15700.45180.36560.056*
H330.06630.29010.36350.056*
H340.05970.44000.29830.056*
N20.1787 (3)0.4311 (3)0.4108 (2)0.0341 (6)
H250.19440.32420.41150.041*
O30.3635 (3)0.2058 (3)0.4110 (2)0.0472 (7)
O40.6200 (2)0.5899 (3)0.37485 (18)0.0418 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.032 (2)0.0401 (19)0.080 (3)0.0035 (15)0.0196 (19)0.002 (2)
C20.0263 (15)0.0337 (16)0.0336 (15)0.0006 (12)0.0100 (12)0.0033 (13)
C30.0267 (15)0.0322 (15)0.0324 (14)0.0005 (12)0.0096 (11)0.0028 (13)
C40.0285 (16)0.0407 (18)0.0424 (17)0.0043 (14)0.0132 (13)0.0039 (15)
C50.039 (2)0.0408 (19)0.061 (2)0.0109 (16)0.0206 (18)0.0113 (18)
C60.0273 (15)0.0323 (15)0.0336 (15)0.0007 (12)0.0077 (12)0.0000 (13)
C70.0221 (14)0.0322 (15)0.0404 (16)0.0024 (12)0.0074 (12)0.0036 (14)
C80.0240 (14)0.0258 (13)0.0380 (15)0.0005 (11)0.0093 (12)0.0014 (12)
C90.0254 (15)0.0369 (16)0.0394 (16)0.0027 (13)0.0103 (12)0.0002 (14)
C100.0348 (18)0.0418 (18)0.0366 (16)0.0046 (14)0.0112 (14)0.0006 (15)
C110.0349 (17)0.0395 (17)0.0367 (16)0.0039 (15)0.0032 (13)0.0003 (15)
C120.0267 (15)0.0312 (15)0.0459 (17)0.0056 (13)0.0064 (13)0.0012 (14)
C130.0250 (14)0.0281 (14)0.0417 (16)0.0025 (12)0.0113 (12)0.0009 (13)
C140.0330 (17)0.053 (2)0.0373 (16)0.0049 (16)0.0109 (14)0.0009 (16)
N10.0231 (13)0.0320 (13)0.0425 (14)0.0017 (10)0.0056 (11)0.0029 (11)
O10.0307 (13)0.0320 (12)0.0555 (15)0.0020 (10)0.0129 (11)0.0031 (11)
O20.0260 (13)0.0546 (16)0.089 (2)0.0059 (12)0.0179 (14)0.0152 (16)
C150.0285 (17)0.0375 (17)0.059 (2)0.0022 (14)0.0153 (16)0.0033 (16)
C160.0283 (16)0.0312 (15)0.0410 (17)0.0016 (12)0.0134 (13)0.0043 (14)
C170.0245 (14)0.0317 (15)0.0339 (14)0.0030 (12)0.0091 (11)0.0019 (13)
C180.0267 (15)0.0382 (16)0.0345 (15)0.0058 (13)0.0098 (12)0.0018 (14)
C190.0350 (19)0.0384 (18)0.067 (2)0.0026 (15)0.0194 (17)0.0120 (18)
C200.0262 (14)0.0303 (14)0.0357 (14)0.0023 (12)0.0107 (12)0.0010 (12)
C210.0227 (14)0.0301 (15)0.0442 (16)0.0031 (12)0.0123 (12)0.0020 (14)
C220.0217 (13)0.0239 (13)0.0385 (15)0.0015 (10)0.0075 (11)0.0019 (12)
C230.0242 (14)0.0308 (15)0.0409 (16)0.0016 (12)0.0055 (12)0.0029 (13)
C240.0342 (17)0.0321 (15)0.0389 (16)0.0004 (13)0.0016 (14)0.0023 (14)
C250.0420 (19)0.0315 (15)0.0354 (15)0.0029 (14)0.0085 (14)0.0047 (14)
C260.0314 (16)0.0313 (15)0.0400 (16)0.0008 (13)0.0147 (13)0.0022 (14)
C270.0243 (14)0.0277 (13)0.0379 (15)0.0013 (11)0.0088 (11)0.0005 (13)
C280.0285 (16)0.0476 (19)0.0355 (16)0.0029 (14)0.0079 (13)0.0009 (15)
N20.0254 (13)0.0303 (13)0.0510 (16)0.0010 (10)0.0175 (12)0.0009 (12)
O30.0349 (14)0.0309 (12)0.082 (2)0.0018 (10)0.0256 (14)0.0005 (13)
O40.0253 (11)0.0447 (13)0.0583 (15)0.0045 (10)0.0152 (11)0.0020 (13)
Geometric parameters (Å, º) top
C1—C21.504 (5)C15—C161.510 (5)
C1—H10.9800C15—H180.9800
C1—H20.9800C15—H190.9800
C1—H30.9800C15—H200.9800
C2—O11.246 (4)C16—O31.236 (4)
C2—C31.453 (4)C16—C171.455 (4)
C3—C61.399 (4)C17—C201.396 (4)
C3—C41.472 (5)C17—C181.468 (4)
C4—O21.224 (4)C18—O41.228 (4)
C4—C51.517 (5)C18—C191.518 (5)
C5—H40.9800C19—H210.9800
C5—H50.9800C19—H220.9800
C5—H60.9800C19—H230.9800
C6—N11.311 (4)C20—N21.321 (4)
C6—H70.9500C20—H240.9500
C7—N11.470 (4)C21—N21.463 (4)
C7—C81.522 (4)C21—C281.524 (5)
C7—C141.527 (5)C21—C221.534 (4)
C7—H91.0000C21—H261.0000
C8—C91.394 (4)C22—C231.387 (4)
C8—C131.399 (4)C22—C271.400 (4)
C9—C101.383 (5)C23—C241.388 (5)
C9—H100.9500C23—H270.9500
C10—C111.392 (5)C24—C251.392 (5)
C10—H110.9500C24—H280.9500
C11—C121.390 (5)C25—C261.387 (5)
C11—H120.9500C25—H290.9500
C12—C131.385 (5)C26—C271.392 (4)
C12—H130.9500C26—H300.9500
C13—H140.9500C27—H310.9500
C14—H150.9800C28—H320.9800
C14—H160.9800C28—H330.9800
C14—H170.9800C28—H340.9800
N1—H80.8800N2—H250.8800
C2—C1—H1109.5C16—C15—H18109.5
C2—C1—H2109.5C16—C15—H19109.5
H1—C1—H2109.5H18—C15—H19109.5
C2—C1—H3109.5C16—C15—H20109.5
H1—C1—H3109.5H18—C15—H20109.5
H2—C1—H3109.5H19—C15—H20109.5
O1—C2—C3120.7 (3)O3—C16—C17121.0 (3)
O1—C2—C1117.3 (3)O3—C16—C15117.5 (3)
C3—C2—C1122.0 (3)C17—C16—C15121.5 (3)
C6—C3—C2119.0 (3)C20—C17—C16119.0 (3)
C6—C3—C4118.1 (3)C20—C17—C18118.2 (3)
C2—C3—C4122.9 (3)C16—C17—C18122.8 (3)
O2—C4—C3122.7 (3)O4—C18—C17122.8 (3)
O2—C4—C5117.7 (3)O4—C18—C19117.2 (3)
C3—C4—C5119.5 (3)C17—C18—C19120.1 (3)
C4—C5—H4109.5C18—C19—H21109.5
C4—C5—H5109.5C18—C19—H22109.5
H4—C5—H5109.5H21—C19—H22109.5
C4—C5—H6109.5C18—C19—H23109.5
H4—C5—H6109.5H21—C19—H23109.5
H5—C5—H6109.5H22—C19—H23109.5
N1—C6—C3126.4 (3)N2—C20—C17126.4 (3)
N1—C6—H7116.8N2—C20—H24116.8
C3—C6—H7116.8C17—C20—H24116.8
N1—C7—C8111.0 (3)N2—C21—C28109.8 (3)
N1—C7—C14109.6 (3)N2—C21—C22111.0 (3)
C8—C7—C14112.8 (3)C28—C21—C22112.3 (3)
N1—C7—H9107.8N2—C21—H26107.8
C8—C7—H9107.8C28—C21—H26107.8
C14—C7—H9107.8C22—C21—H26107.8
C9—C8—C13118.0 (3)C23—C22—C27118.6 (3)
C9—C8—C7122.6 (3)C23—C22—C21122.6 (3)
C13—C8—C7119.4 (3)C27—C22—C21118.7 (3)
C10—C9—C8121.3 (3)C22—C23—C24121.0 (3)
C10—C9—H10119.4C22—C23—H27119.5
C8—C9—H10119.4C24—C23—H27119.5
C9—C10—C11120.3 (3)C23—C24—C25120.1 (3)
C9—C10—H11119.9C23—C24—H28119.9
C11—C10—H11119.9C25—C24—H28119.9
C12—C11—C10119.1 (3)C26—C25—C24119.4 (3)
C12—C11—H12120.5C26—C25—H29120.3
C10—C11—H12120.5C24—C25—H29120.3
C13—C12—C11120.5 (3)C25—C26—C27120.4 (3)
C13—C12—H13119.8C25—C26—H30119.8
C11—C12—H13119.8C27—C26—H30119.8
C12—C13—C8120.9 (3)C26—C27—C22120.4 (3)
C12—C13—H14119.6C26—C27—H31119.8
C8—C13—H14119.6C22—C27—H31119.8
C7—C14—H15109.5C21—C28—H32109.5
C7—C14—H16109.5C21—C28—H33109.5
H15—C14—H16109.5H32—C28—H33109.5
C7—C14—H17109.5C21—C28—H34109.5
H15—C14—H17109.5H32—C28—H34109.5
H16—C14—H17109.5H33—C28—H34109.5
C6—N1—C7124.4 (3)C20—N2—C21124.0 (3)
C6—N1—H8117.8C20—N2—H25118.0
C7—N1—H8117.8C21—N2—H25118.0
O1—C2—C3—C61.2 (5)O3—C16—C17—C204.2 (5)
C1—C2—C3—C6177.8 (3)C15—C16—C17—C20174.5 (3)
O1—C2—C3—C4179.4 (3)O3—C16—C17—C18177.2 (3)
C1—C2—C3—C41.6 (5)C15—C16—C17—C184.1 (5)
C6—C3—C4—O2177.2 (4)C20—C17—C18—O4172.0 (3)
C2—C3—C4—O22.2 (5)C16—C17—C18—O46.7 (5)
C6—C3—C4—C52.7 (5)C20—C17—C18—C198.3 (5)
C2—C3—C4—C5177.8 (3)C16—C17—C18—C19173.1 (3)
C2—C3—C6—N11.5 (5)C16—C17—C20—N21.8 (5)
C4—C3—C6—N1179.0 (3)C18—C17—C20—N2179.5 (3)
N1—C7—C8—C94.7 (4)N2—C21—C22—C233.2 (4)
C14—C7—C8—C9128.1 (3)C28—C21—C22—C23126.6 (3)
N1—C7—C8—C13176.5 (3)N2—C21—C22—C27178.7 (3)
C14—C7—C8—C1353.1 (4)C28—C21—C22—C2755.3 (4)
C13—C8—C9—C100.2 (5)C27—C22—C23—C240.4 (5)
C7—C8—C9—C10178.7 (3)C21—C22—C23—C24178.6 (3)
C8—C9—C10—C110.3 (6)C22—C23—C24—C250.9 (5)
C9—C10—C11—C120.4 (6)C23—C24—C25—C260.9 (5)
C10—C11—C12—C130.1 (5)C24—C25—C26—C270.4 (5)
C11—C12—C13—C80.6 (5)C25—C26—C27—C220.0 (5)
C9—C8—C13—C120.6 (5)C23—C22—C27—C260.1 (5)
C7—C8—C13—C12178.3 (3)C21—C22—C27—C26178.2 (3)
C3—C6—N1—C7179.4 (3)C17—C20—N2—C21174.6 (3)
C8—C7—N1—C6119.2 (3)C22—C21—N2—C20112.8 (3)
C14—C7—N1—C6115.5 (4)C28—C21—N2—C20122.4 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H8···O10.881.942.597 (4)131
N2—H25···O30.881.952.603 (4)130
C14—H15···O2i0.982.553.532 (5)175
C14—H17···O40.982.663.482 (5)142
C28—H32···O4i0.982.543.512 (5)173
Symmetry code: (i) x1, y, z.
Comparison of torsion angles in the crystal structures of 13 and from theoretical DFT calculations top
CompoundTorsion angleCrystal structure determinationDFT calculation
1C8—C7—N—C6–94.4 (1)–107.8
2C8—C7—N—C6-14.03 (14)0.0
C9—C7—N—C6–134.31 (11)–120.8
C10—C7—N—C6107.27 (11)120.8
3C14—C7—N1—C6115.5 (4); 122.4 (3)*–167.3
C8—C7—N1—C6–119.2 (4); –112.8 (3)*–43.3
*Values for the comparable bond in the second molecule.
 

Funding information

We acknowledge the financial support of the Open Access Publication Fund of the Martin-Luther-University Halle-Wittenberg.

References

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