Structure of 2-chloro-N-(p-tolyl)propanamide

Two independent samples of the title compound, alternatively 2-chloro-N-(4-methylphenyl)propanamide, C10H12ClNO, 1, were studied using Cu K alpha, 1a, and Mo K alpha, 1b, radiation as part of a continuous crystallization study. The molecule crystallizes with disorder in the Cl/terminal methyl positions [occupancies for the major disorder component of 0.783 (2) in 1a and and 0.768 (2) in 1b] and exhibits N-C bond lengths of 1.3448 (19), 1.344 (2) angstrom, C=O bond lengths of 1.2233 (18) and 1.2245 (19) angstrom and an acetamide moiety C-N-C-C torsion angle of 179.00 (13), 178.97 (14) degrees for 1a and 1b, respectively. In the crystal, chains along the a axis are formed via N-H center dot center dot center dot O hydrogen bonds between acetamide groups, as well as C-H center dot center dot center dot O interactions. These chains arrange themselves into parallel running stacks which display weak C-Cl center dot center dot center dot O=C halogen bonding as well as weak C-H center dot center dot center dot pi interactions.