2-Amino-3-methylpyridinium 4-methoxybenzoate

Abstract

In the title molecular salt, C 6 H 9 N 2 + ÁC 8 H 7 O 3 À , the cation is protonated at its pyridine N atom and is inclined by 3.39 (9) to the benzene ring of the anion, which is deprotonated at the carboxyl group. The methoxy group is twisted with respect to the benzene ring to which it is attached, the methyl C atom deviating from the ring plane by 0.023 (2) Å . In the crystal, the anions and cations are linked by two N-HÁ Á ÁO hydrogen bonds, forming an R 2 2 (8) ring motif. They are also linked by a weak offset -interaction [centroid-to-centroid distance = 3.890 (1) Å ]. The anions and cations are further connected through N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming slabs parallel to (001). Structure descriptionPyridine derivatives have been shown to exhibit anticancer (Girgis et al. 2006) and antiviral (Hamdouchi et al., 1999) activities. As part of our studies in this area we synthesized the title compound and report herein on its synthesis and crystal structure.The geometric parameters of the title compound, Fig. 1, are comparable with those reported for similar structures (Babu et al., 2014;Sivakumar et al., 2016). The asymmetric unit contains a 2-amino-3-methylpyridinium cation, which is protonated at the pyridine N atom and a 4-methoxybenzoate anion which is deprotonated at the carboxyl group. They are linked by two N-HÁ Á ÁO hydrogen bonds, forming R 2 2 (8) ring-motifs (Table 1 and Fig. 2). They are also linked by a weak offset -interaction [Cg1Á Á ÁCg2 = 3.890 (1) Å , interplanar distance = 3.487 (1) Å , slippage = 1.896 Å , Cg1 and Cg2 are the centroids of rings C1-C6 and N1/C9-C13, respectively]. The benzene ring (C1-C6) makes a dihedral angle of 3.39 (9) with the pyridine ring (N1/C9-C13). The methoxy group is twisted with respect to the benzene ring, the methyl atom C17 deviating from the ring plane by 0.023 (2) Å . The mean plane of the methoxy group (C1/O1/C7) is twisted at an angle of 3.49 (17) with respect to the attached benzene ring.