1-Chloro-3-ethynyl-2,4-dimethoxybenzene

Abstract

C10H9ClO2, Mr = 196.6, monoclinic, P2(1)/c, a = 10.8146 (6), b = 8.8883 (8), c = 10.4110 (9) A, beta = 103.101 (6) degrees, V = 974.7 (3) A3, Z = 4, Dx = 1.340 g cm-3, lambda(Cu K alpha) = 1.54184 A, mu = 32.27 cm-1, F(000) = 408, T = 296 K, R = 0.061 for 1405 observations (of 2004 unique data). The molecule contains two methoxy groups; one is nearly coplanar with the benzenoid ring, with C-C-O-C torsion angle -5.2 (5) degrees, and the other, which resides between the chloro and the ethynyl groups, is nearly orthogonal, with the corresponding torsion angle 86.5 (4) degrees. The coplanar methoxy has an angle about O of 118.3 (2) degrees and the orthogonal, 114.7 (1) degrees. The O-CH3 distance in the coplanar methoxy is 1.426 (2) A compared to 1.439 (2) A in the orthogonal. The six-membered ring is planar, with maximum deviation 0.008 (3) A. The C-Cl distance is 1.734 (2) A, and the triple-bond distance is 1.179 (3) A. The ethynyl group forms a nearly linear C-H...O contact with the O atom of the orthogonal methoxy on a glide-related molecule, having C...O distance 3.293 (3) A and angle at H of 167 (3) degrees.