3-Chloro-4-dimethylaminothioangelicin.

C13H10ClO2NS, Mr = 279.75, monoclinic, P2(1)/a, a = 14.490 (3), b = 22.598 (5), c = 7.336 (2) A, beta = 92.4 (1) degree, U = 2400 (1) A3, Z = 8, D chi = 1.548 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 2.07 cm-1, F(000) = 1152, room temperature, R = 0.037 for 2423 independent reflections with I greater than or equal to 3 sigma(I). Each unit cell contains two independent molecules which differ mainly in the orientation of their N(CH3)2 groups. The two tricyclic moieties of each molecule are not coplanar, the pyran ring being tilted by 7.9 (1) degree with respect to the benzene ring in molecule 1 and by 8.7 (1) degree in molecule 2. There are weak interactions between the molecules involving the carboxylic O atoms and the H atoms of the phenyl moieties.