organic compounds
Valyl benzyl ester chloride
aDepartment of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, bDepartment of Chemistry, V. V. Puram College of Science, Bangalore 560 004, India, cDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India, and dSequent Scientific limited, New Mangalore 575 011, India
*Correspondence e-mail: mkubicki@amu.edu.pl
In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride), C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2) Å from the least-squares plane, and makes a dihedral angle of 28.92 (16)° with the phenyl ring. The is organized by N—H⋯Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H⋯Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.
Related literature
For valsartan, see: Black et al. (1997); Buhlmayer et al. (1994). For related structures, see: Bryndal et al. (2006); Jaeger et al. (2003); Nastopoulos et al. (1987). For a description of the Cambridge Structural Database, see: Allen (2002). For graph-set motifs, see: Bernstein et al. (1995).
Experimental
Crystal data
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Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536810000176/is2507sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810000176/is2507Isup2.hkl
The title compound was obtained as a gift sample from Cipla, Bangalore, India. X-ray quality crystals were obtained from slow evaporation of an aqueous solution (m.p. 409–412 K).
Positional and isotropic thermal parameters of the H atoms from the NH3 group were freely refined. All other H atoms were put in the calculated idealized positions (C—H = 0.93–0.97 Å) and refined as riding, with Uiso's set at 1.2 (1.4 for methyl groups) times the Ueq's of appropriate carrier atoms.
The title compound (I, Scheme 1), valyl benzyl ester chloride [1-(benzyloxy)-3-methyl-1-oxobutan-2-aminium chloride], is a reactant (Buhlmayer et al., 1994) for the synthesis of valsartan, which belongs to the class of angiotensin II receptor antagonists (Black et al., 1997).
The ester fragment C2/C1/O1/O11/C12 (Fig. 1) is in a good approximation planar, maximum deviation from the least squares plane being 0.040 (2) Å, and it makes a dihedral angle of 28.92 (16)° with the plane of the phenyl ring [planar within 0.009 (3) Å]. The C2—C3 bond is almost perpendicular to the plane of ester group, the torsion angle O11—C1—C2—C3 being -82.2 (3)°.
In the
the N—H···Cl hydrogen bonds between the cations and chloride anions join the ionic components into the chains along the b direction (Fig. 2 and Table 1). Within these chains there are additional relatively short and linear C—H···O hydrogen bonds involving the C=O oxygen atom. Using graph-set notation (Bernstein et al., 1995), there are two second-order antiparallel C21(4) chains which are interconnected by another hydrogen bonds into two different kinds of third-order hydrogen bonded R42(8) rings. Similar packing was observed in a number of the amino acid ester halides, and it always was connected with the unit-cell parameter of ca 5.5 Å. In the Cambridge Structural Database (Allen, 2002), there are 25 organic structures of the amino acid ester halides, and 10 of them display similar crystal packing and appropriate unit-cell parameter. For instance, L-tyrosyl methyl ester chloride (Bryndal et al., 2006) crystallizes in P212121 with one of the unit-cell parameters 5.424 (2) Å, valyl methyl ester chloride (Jaeger et al., 2003) - also P212121, with 5.894 (2) Å, and (S-benzyl-L-cysteine methyl ester hydrochloride (Nastopoulos et al., 1987) - in P21 with c = 5.211 (2) Å.The coordination of Cl ion by three hydrogen bonded N—H groups might be described as a trigonal pyramid with N—H groups at the base and Cl ion in the apex. The H···Cl···H angles are in the range 77–118°, and the sum of these angles is 277°. It might be noted that if these coordination is described as tetragonal, the empty coordination place is taken by relatively strong C—H(methyl)···Cl hydrogen bond (Table 1).
For valsartan, see: Black et al. (1997); Buhlmayer et al. (1994). For related structures, see: Bryndal et al. (2006); Jaeger et al. (2003); Nastopoulos et al. (1987). For a description of the Cambridge Structural Database, see: Allen (2002). For graph-set motifs, see: Bernstein et al. (1995).
Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell
CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).Fig. 1. Anisotropic ellipsoid representation of the title compound together with atom labelling scheme. The ellipsoids are drawn at 50% probability level, hydrogen atoms are depicted as spheres with arbitrary radii. Hydrogen bond is shown as dashed line. | |
Fig. 2. The hydrogen-bonded structure of the title compound. Hydrogen bonds are shown as dashed lines. [Symmetry codes: (i) 1 - x, 1/2 + y, -z; (ii) x, 1 + y, z; (iii) 1 - x, -1/2 + y, -z; (iv) x, -1 + y, z; (v) 1 - x, -3/2 + y, -z.] |
C12H18NO2+·Cl− | F(000) = 260 |
Mr = 243.72 | Dx = 1.184 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 1449 reflections |
a = 9.705 (1) Å | θ = 2.1–26.9° |
b = 5.406 (1) Å | µ = 0.27 mm−1 |
c = 13.116 (2) Å | T = 295 K |
β = 96.58 (1)° | Prism, colourless |
V = 683.60 (18) Å3 | 0.4 × 0.2 × 0.2 mm |
Z = 2 |
Oxford Diffraction Xcalibur Sapphire2 diffractometer | 2010 independent reflections |
Radiation source: Nova (Mo) X-ray Source | 1652 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
Detector resolution: 5.2679 pixels mm-1 | θmax = 26.9°, θmin = 2.1° |
ω scan | h = −10→12 |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) | k = −4→6 |
Tmin = 0.741, Tmax = 0.948 | l = −15→11 |
2649 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.034 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.077 | w = 1/[σ2(Fo2) + (0.040P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
2010 reflections | Δρmax = 0.17 e Å−3 |
159 parameters | Δρmin = −0.24 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 530 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.02 (8) |
C12H18NO2+·Cl− | V = 683.60 (18) Å3 |
Mr = 243.72 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 9.705 (1) Å | µ = 0.27 mm−1 |
b = 5.406 (1) Å | T = 295 K |
c = 13.116 (2) Å | 0.4 × 0.2 × 0.2 mm |
β = 96.58 (1)° |
Oxford Diffraction Xcalibur Sapphire2 diffractometer | 2010 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) | 1652 reflections with I > 2σ(I) |
Tmin = 0.741, Tmax = 0.948 | Rint = 0.023 |
2649 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.077 | Δρmax = 0.17 e Å−3 |
S = 1.06 | Δρmin = −0.24 e Å−3 |
2010 reflections | Absolute structure: Flack (1983), 530 Friedel pairs |
159 parameters | Absolute structure parameter: 0.02 (8) |
1 restraint |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.6929 (3) | 1.0154 (5) | 0.2145 (2) | 0.0492 (6) | |
O11 | 0.7115 (2) | 0.9397 (3) | 0.31112 (13) | 0.0744 (6) | |
C12 | 0.6987 (5) | 1.1297 (7) | 0.3890 (2) | 0.0963 (12) | |
H12A | 0.6100 | 1.2132 | 0.3756 | 0.116* | |
H12B | 0.7719 | 1.2516 | 0.3878 | 0.116* | |
C13 | 0.7099 (4) | 1.0030 (7) | 0.4919 (2) | 0.0766 (10) | |
C14 | 0.6351 (4) | 1.0998 (9) | 0.5647 (2) | 0.1010 (13) | |
H14 | 0.5791 | 1.2380 | 0.5506 | 0.121* | |
C15 | 0.6452 (6) | 0.9849 (14) | 0.6612 (3) | 0.128 (2) | |
H15 | 0.5947 | 1.0479 | 0.7114 | 0.154* | |
C16 | 0.7258 (7) | 0.7875 (13) | 0.6824 (4) | 0.137 (3) | |
H16 | 0.7314 | 0.7146 | 0.7469 | 0.165* | |
C17 | 0.7994 (6) | 0.6933 (11) | 0.6098 (4) | 0.1375 (18) | |
H17 | 0.8544 | 0.5539 | 0.6243 | 0.165* | |
C18 | 0.7931 (5) | 0.8035 (8) | 0.5143 (3) | 0.1053 (14) | |
H18 | 0.8459 | 0.7411 | 0.4653 | 0.126* | |
O1 | 0.6602 (2) | 1.2196 (4) | 0.18837 (14) | 0.0702 (6) | |
C2 | 0.7212 (2) | 0.8078 (4) | 0.14310 (17) | 0.0454 (6) | |
H2 | 0.6851 | 0.6536 | 0.1691 | 0.054* | |
N2 | 0.6429 (2) | 0.8642 (6) | 0.04138 (15) | 0.0476 (5) | |
H2A | 0.678 (3) | 1.021 (7) | 0.013 (2) | 0.071 (10)* | |
H2B | 0.649 (3) | 0.740 (6) | −0.0041 (19) | 0.049 (8)* | |
H2C | 0.546 (3) | 0.867 (7) | 0.0479 (16) | 0.064 (7)* | |
C3 | 0.8749 (3) | 0.7732 (5) | 0.1324 (2) | 0.0558 (7) | |
H3 | 0.8806 | 0.6464 | 0.0796 | 0.067* | |
C4 | 0.9422 (3) | 1.0029 (7) | 0.0953 (3) | 0.0886 (11) | |
H4A | 0.9374 | 1.1335 | 0.1444 | 0.124* | |
H4B | 0.8945 | 1.0526 | 0.0304 | 0.124* | |
H4C | 1.0375 | 0.9688 | 0.0876 | 0.124* | |
C5 | 0.9560 (3) | 0.6756 (7) | 0.2299 (3) | 0.0844 (10) | |
H5A | 1.0481 | 0.6321 | 0.2163 | 0.118* | |
H5B | 0.9103 | 0.5321 | 0.2530 | 0.118* | |
H5C | 0.9609 | 0.8010 | 0.2820 | 0.118* | |
Cl1 | 0.33538 (6) | 0.86692 (12) | 0.08481 (4) | 0.05096 (19) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0545 (16) | 0.0364 (15) | 0.0597 (15) | −0.0021 (13) | 0.0201 (12) | 0.0033 (13) |
O11 | 0.1207 (16) | 0.0510 (14) | 0.0542 (10) | 0.0173 (11) | 0.0221 (10) | 0.0029 (8) |
C12 | 0.171 (4) | 0.060 (2) | 0.0638 (19) | 0.016 (3) | 0.040 (2) | −0.0077 (17) |
C13 | 0.107 (3) | 0.068 (2) | 0.0550 (17) | −0.004 (2) | 0.0097 (17) | −0.0008 (16) |
C14 | 0.117 (3) | 0.125 (4) | 0.062 (2) | −0.008 (3) | 0.019 (2) | −0.018 (2) |
C15 | 0.146 (5) | 0.179 (6) | 0.063 (3) | −0.054 (4) | 0.025 (3) | −0.021 (3) |
C16 | 0.181 (6) | 0.160 (6) | 0.064 (3) | −0.083 (5) | −0.015 (3) | 0.021 (3) |
C17 | 0.190 (5) | 0.123 (4) | 0.089 (3) | 0.000 (4) | −0.030 (3) | 0.027 (3) |
C18 | 0.143 (4) | 0.094 (4) | 0.078 (2) | 0.013 (3) | 0.011 (2) | 0.013 (2) |
O1 | 0.1138 (17) | 0.0358 (12) | 0.0648 (12) | 0.0101 (11) | 0.0265 (11) | 0.0051 (9) |
C2 | 0.0508 (14) | 0.0325 (16) | 0.0541 (13) | −0.0006 (11) | 0.0122 (10) | 0.0044 (10) |
N2 | 0.0450 (12) | 0.0398 (12) | 0.0593 (11) | −0.0043 (17) | 0.0117 (9) | −0.0056 (15) |
C3 | 0.0524 (16) | 0.0503 (16) | 0.0659 (16) | 0.0095 (13) | 0.0117 (13) | −0.0058 (13) |
C4 | 0.055 (2) | 0.090 (3) | 0.123 (3) | −0.002 (2) | 0.0227 (18) | 0.021 (2) |
C5 | 0.066 (2) | 0.082 (3) | 0.100 (2) | 0.0181 (19) | −0.0083 (17) | 0.0045 (19) |
Cl1 | 0.0535 (3) | 0.0506 (4) | 0.0506 (3) | 0.0008 (4) | 0.0137 (2) | 0.0006 (3) |
C1—O1 | 1.188 (3) | C18—H18 | 0.9300 |
C1—O11 | 1.324 (3) | C2—N2 | 1.489 (3) |
C1—C2 | 1.507 (3) | C2—C3 | 1.526 (3) |
O11—C12 | 1.464 (4) | C2—H2 | 0.9800 |
C12—C13 | 1.506 (4) | N2—H2A | 1.00 (3) |
C12—H12A | 0.9700 | N2—H2B | 0.90 (3) |
C12—H12B | 0.9700 | N2—H2C | 0.96 (3) |
C13—C18 | 1.359 (5) | C3—C4 | 1.509 (4) |
C13—C14 | 1.368 (5) | C3—C5 | 1.518 (4) |
C14—C15 | 1.403 (6) | C3—H3 | 0.9800 |
C14—H14 | 0.9300 | C4—H4A | 0.9600 |
C15—C16 | 1.334 (7) | C4—H4B | 0.9600 |
C15—H15 | 0.9300 | C4—H4C | 0.9600 |
C16—C17 | 1.353 (8) | C5—H5A | 0.9600 |
C16—H16 | 0.9300 | C5—H5B | 0.9600 |
C17—C18 | 1.382 (6) | C5—H5C | 0.9600 |
C17—H17 | 0.9300 | ||
O1—C1—O11 | 124.5 (3) | N2—C2—C3 | 110.25 (19) |
O1—C1—C2 | 125.0 (2) | C1—C2—C3 | 113.5 (2) |
O11—C1—C2 | 110.5 (2) | N2—C2—H2 | 108.6 |
C1—O11—C12 | 115.9 (2) | C1—C2—H2 | 108.6 |
O11—C12—C13 | 107.6 (3) | C3—C2—H2 | 108.6 |
O11—C12—H12A | 110.2 | C2—N2—H2A | 110.6 (17) |
C13—C12—H12A | 110.2 | C2—N2—H2B | 112.0 (16) |
O11—C12—H12B | 110.2 | H2A—N2—H2B | 109.2 (19) |
C13—C12—H12B | 110.2 | C2—N2—H2C | 109.3 (13) |
H12A—C12—H12B | 108.5 | H2A—N2—H2C | 113 (3) |
C18—C13—C14 | 120.1 (4) | H2B—N2—H2C | 102 (3) |
C18—C13—C12 | 122.4 (3) | C4—C3—C5 | 110.8 (3) |
C14—C13—C12 | 117.5 (4) | C4—C3—C2 | 113.1 (2) |
C13—C14—C15 | 118.2 (5) | C5—C3—C2 | 112.5 (2) |
C13—C14—H14 | 120.9 | C4—C3—H3 | 106.6 |
C15—C14—H14 | 120.9 | C5—C3—H3 | 106.6 |
C16—C15—C14 | 121.4 (5) | C2—C3—H3 | 106.6 |
C16—C15—H15 | 119.3 | C3—C4—H4A | 109.5 |
C14—C15—H15 | 119.3 | C3—C4—H4B | 109.5 |
C15—C16—C17 | 119.9 (5) | H4A—C4—H4B | 109.5 |
C15—C16—H16 | 120.0 | C3—C4—H4C | 109.5 |
C17—C16—H16 | 120.0 | H4A—C4—H4C | 109.5 |
C16—C17—C18 | 120.2 (6) | H4B—C4—H4C | 109.5 |
C16—C17—H17 | 119.9 | C3—C5—H5A | 109.5 |
C18—C17—H17 | 119.9 | C3—C5—H5B | 109.5 |
C13—C18—C17 | 120.1 (4) | H5A—C5—H5B | 109.5 |
C13—C18—H18 | 119.9 | C3—C5—H5C | 109.5 |
C17—C18—H18 | 119.9 | H5A—C5—H5C | 109.5 |
N2—C2—C1 | 107.1 (2) | H5B—C5—H5C | 109.5 |
O1—C1—O11—C12 | −4.1 (4) | C12—C13—C18—C17 | −179.8 (4) |
C2—C1—O11—C12 | 175.1 (3) | C16—C17—C18—C13 | −1.8 (7) |
C1—O11—C12—C13 | 174.8 (3) | O1—C1—C2—N2 | −25.0 (4) |
O11—C12—C13—C18 | 34.5 (5) | O11—C1—C2—N2 | 155.9 (2) |
O11—C12—C13—C14 | −147.1 (3) | O1—C1—C2—C3 | 96.9 (3) |
C18—C13—C14—C15 | −1.1 (6) | O11—C1—C2—C3 | −82.2 (3) |
C12—C13—C14—C15 | −179.5 (4) | N2—C2—C3—C4 | 62.6 (3) |
C13—C14—C15—C16 | 0.4 (6) | C1—C2—C3—C4 | −57.6 (3) |
C14—C15—C16—C17 | −0.3 (7) | N2—C2—C3—C5 | −170.9 (3) |
C15—C16—C17—C18 | 1.1 (8) | C1—C2—C3—C5 | 69.0 (3) |
C14—C13—C18—C17 | 1.9 (6) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1i | 0.98 | 2.38 | 3.301 (3) | 157 |
N2—H2A···Cl1ii | 1.00 (3) | 2.26 (4) | 3.201 (3) | 156 (2) |
N2—H2B···Cl1iii | 0.90 (3) | 2.29 (3) | 3.177 (3) | 166 (2) |
N2—H2C···Cl1 | 0.96 (3) | 2.15 (3) | 3.101 (2) | 172.1 (18) |
C4—H4C···Cl1iv | 0.96 | 2.95 | 3.904 (3) | 175 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z; (iii) −x+1, y−1/2, −z; (iv) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C12H18NO2+·Cl− |
Mr | 243.72 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 295 |
a, b, c (Å) | 9.705 (1), 5.406 (1), 13.116 (2) |
β (°) | 96.58 (1) |
V (Å3) | 683.60 (18) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.4 × 0.2 × 0.2 |
Data collection | |
Diffractometer | Oxford Diffraction Xcalibur Sapphire2 |
Absorption correction | Multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) |
Tmin, Tmax | 0.741, 0.948 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2649, 2010, 1652 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.636 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.077, 1.06 |
No. of reflections | 2010 |
No. of parameters | 159 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.17, −0.24 |
Absolute structure | Flack (1983), 530 Friedel pairs |
Absolute structure parameter | 0.02 (8) |
Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 2008), Stereochemical Workstation Operation Manual (Siemens, 1989).
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1i | 0.98 | 2.38 | 3.301 (3) | 157.2 |
N2—H2A···Cl1ii | 1.00 (3) | 2.26 (4) | 3.201 (3) | 156 (2) |
N2—H2B···Cl1iii | 0.90 (3) | 2.29 (3) | 3.177 (3) | 166 (2) |
N2—H2C···Cl1 | 0.96 (3) | 2.15 (3) | 3.101 (2) | 172.1 (18) |
C4—H4C···Cl1iv | 0.96 | 2.95 | 3.904 (3) | 174.7 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z; (iii) −x+1, y−1/2, −z; (iv) x+1, y, z. |
Acknowledgements
BPS thanks Cipla, Bangalore for the gift of a sample of the title compound
References
Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Altomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343–350. CrossRef Web of Science IUCr Journals Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Black, H. R., Graff, A., Shute, D., Stoltz, R., Ruff, D. & Levine, J. (1997). J. Hum. Hypertens. 11, 483–489. CrossRef CAS PubMed Web of Science Google Scholar
Bryndal, I., Jaremko, M., Jaremko, L. & Lis, T. (2006). Acta Cryst. C62, o111–o114. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Buhlmayer, P., Furet, P., Criscione, L., deGasparo, M., Whitebread, S., Schmidlin, T., Lattmann, R. & Wood, J. (1994). Bioorg. Med. Chem. Lett. 4, 29–34. CrossRef CAS Web of Science Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Jaeger, M., Steglich, W. & Polborn, K. (2003). Private communication (refcode HABXAK). CCDC, Union Road, Cambridge, England. Google Scholar
Nastopoulos, V., Germain, G., Cordopatis, P. & Voliotis, S. (1987). Acta Cryst. C43, 375–376. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1989). Stereochemical Workstation Operation Manual. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar
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The title compound (I, Scheme 1), valyl benzyl ester chloride [1-(benzyloxy)-3-methyl-1-oxobutan-2-aminium chloride], is a reactant (Buhlmayer et al., 1994) for the synthesis of valsartan, which belongs to the class of angiotensin II receptor antagonists (Black et al., 1997).
The ester fragment C2/C1/O1/O11/C12 (Fig. 1) is in a good approximation planar, maximum deviation from the least squares plane being 0.040 (2) Å, and it makes a dihedral angle of 28.92 (16)° with the plane of the phenyl ring [planar within 0.009 (3) Å]. The C2—C3 bond is almost perpendicular to the plane of ester group, the torsion angle O11—C1—C2—C3 being -82.2 (3)°.
In the crystal structure, the N—H···Cl hydrogen bonds between the cations and chloride anions join the ionic components into the chains along the b direction (Fig. 2 and Table 1). Within these chains there are additional relatively short and linear C—H···O hydrogen bonds involving the C=O oxygen atom. Using graph-set notation (Bernstein et al., 1995), there are two second-order antiparallel C21(4) chains which are interconnected by another hydrogen bonds into two different kinds of third-order hydrogen bonded R42(8) rings. Similar packing was observed in a number of the amino acid ester halides, and it always was connected with the unit-cell parameter of ca 5.5 Å. In the Cambridge Structural Database (Allen, 2002), there are 25 organic structures of the amino acid ester halides, and 10 of them display similar crystal packing and appropriate unit-cell parameter. For instance, L-tyrosyl methyl ester chloride (Bryndal et al., 2006) crystallizes in P212121 space group with one of the unit-cell parameters 5.424 (2) Å, valyl methyl ester chloride (Jaeger et al., 2003) - also P212121, with 5.894 (2) Å, and (S-benzyl-L-cysteine methyl ester hydrochloride (Nastopoulos et al., 1987) - in P21 with c = 5.211 (2) Å.
The coordination of Cl ion by three hydrogen bonded N—H groups might be described as a trigonal pyramid with N—H groups at the base and Cl ion in the apex. The H···Cl···H angles are in the range 77–118°, and the sum of these angles is 277°. It might be noted that if these coordination is described as tetragonal, the empty coordination place is taken by relatively strong C—H(methyl)···Cl hydrogen bond (Table 1).