Crystal structure of N-allyl-4-methylbenzenesulfonamide

In the crystal structure of the title sulfonamide, intermolecular N—H⋯O hydrogen bonds are present between sulfonamide groups, as well as offset π–π interactions.


Chemical context
The sulfonamide moiety has been widely studied and its application in drug design has been reported (Qadir et al., 2015;Rehman et al., 2017;Gul et al., 2018). Sulfa drugs, which incorporate the sulfonamide moiety, have found applications as antibacterial, anticancer, antifungal, anti-inflammatory, and antiviral agents (Alaoui et al., 2017).
The synthesis of sulfonamides generally relies on the use of sulfonyl chlorides as electrophilic partners that react with nucleophilic amines. According to the current state of knowledge in the field, the use of sulfonyl chlorides as electrophilic substrates in the synthesis of sulfonamides suffers from some drawbacks. One such drawback is the difficulty in handling and storage (Caddick et al., 2004). Other alternatives to sulfonyl chlorides have been reported (Parumala & Peddinti, 2016;Yang & Tian, 2017). Nucleophilic acyl substitution is the mechanism that describes the reaction between a carboxylic acid derivative such as acid chloride with an amine to form the corresponding amide. The mechanism of the reaction between sulfonyl chlorides and amines is analogous to nucleophilic acyl substitution, except that it occurs at the sulfonyl group and not the carbonyl group (Um et al., 2013).
Recently, we have been particularly interested in the structural motif of sulfonamide compounds that are known to The structure of Sulefonur. modulate 5-HT 6 receptor activity and are used for the treatment of CNS diseases and disorders (Blass, 2016). We are also interested in the therapeutic application of sulfonamide molecules used for chondrogenic differentiation (Choi et al., 2016), and for the treatment of cancer (Gul et al., 2018). Fig. 1 shows the structure of Sulefonur, which has been reported as a potent anticancer sulfonamide drug candidate and is under anticancer clinical trials (Gul et al., 2018). As part of our ongoing effort to synthesize small sulfonamide molecules that mimic the structural motifs of known sulfonamide drug candidates, we synthesized the title compound, C 10 H 13 NO 2 S, (I) and determined its crystal structure from single crystal X-ray diffraction data.

Structural commentary
The molecular structure of compound (I), which was solved in the triclinic space group P1, is shown in Fig. 2. The S-O bond lengths of 1.4282 (17) and 1.4353 (17) Å and the O1-S1-O2 bond angle of 118.87 (11) are typical for sulfonamide moieties. The S1-N1 bond length is 1.617 (2) Å , and the C1-N1-S1-C4 torsion angle is À61.0 (2) . The molecular structure of the title compound, showing the atom labeling. Displacement ellipsoids are drawn at the 50% probability level.

Figure 4
A view along the a axis of the title compound showing the supramolecular ribbons assembled via N-HÁ Á ÁO hydrogen bonds (blue, dashed lines) andinteractions (red, dotted lines).
dimers of compound (I) are formed through intermolecular hydrogen bonds between the sulfonamide N-H group and an O atom of a neighbouring sulfonamide group (Fig. 3). The N1Á Á ÁO2 i distance of 2.900 (3) Å suggests interactions of medium strength with a nearly linear N-HÁ Á ÁO hydrogen bond of 174 (3) ( Table 1). These dimers are then linked through offsetinteractions into ribbons that lie along the c axis (Figs. 3, 4). The intercentroid distance CgÁ Á ÁCg ii is 3.8340 (17) Å , with a slippage of 1.320 Å and a plane-to-plane distance between phenyl rings of 3.600 Å [symmetry code (ii) = Àx, Ày, Àz].

Database survey
The Cambridge Structural Database (CSD, Version 5.39, February 2018; Groom et al., 2016) contains 17 structures of p-tolylsulfonamides where there is a -CH 2 -C C group bonded to the sulfonamide-N atom. The alkene group in these structures is a part of, for example, furan rings (DERTIE and DERTOK, Hashmi et al., 2006), an allene (XUDNEP, Lan & Hammond, 2002), and various acyclic systems (BUXYUQ, Kiyokawa et al., 2015;KIHMIY, Lee et al., 2007). While all of the structures listed here display intermolecular hydrogen bonds between sulfonamide groups, none of them displayinteractions between the p-tolylsulfonamide rings as seen in the title compound.

Synthesis and crystallization
Allylamine (1.31 ml, 18 mmol) was added in 20 ml of degassed dichloromethane. This was followed by the addition of pyridine (1.42 ml, 18 mmol). The resulting solution was stirred under an atmosphere of N 2 , followed by the portion-wise addition of p-toluenesulfonyl chloride (3.05 g, 16 mmol). The mixture was stirred at room temperature for 24 h. Reaction completion was verified by using TLC analysis. The mixture was acidified to pH 2-3 using concentrated HCl. After dilution with 20 ml of CH 2 Cl 2 , the organic phase was washed with H 2 O (3 Â 20 ml) and the aqueous layer was back-extracted with CH 2 Cl 2 (20 ml). The combined organic extracts were dried over anhydrous Na 2 SO 4 . After solvent evaporation, the residue was obtained as a yellow solid which was recrystallized in cold ethanol to afford pale-yellow crystals (56%; m.p. 332-333 K).

N-Allyl-4-methylbenzenesulfonamide
Crystal data Special details 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.