Crystal structure of 1,1-dichloro-4-formyl-3-methyl-1a-phenyl-1a,2,3,4-tetrahydro-1H-azirino[1,2-a][1,5]benzodiazepine (C18H16Cl2N2O)

The crystal structure of the title compound, 1,1-dichloro-4-formyl-3-methyl-1a-phenyl-1a,2,3,4-tetrahydro-1H-azirino [1,2-a] [1,5]benzodiazepine (C-18-H16Cl2N2O, M-r=347.76) was crystallized in the monoclinic system, space group P2(1)/n, with cell dimensions a=9.6548(9), b=10.438(2), c=16.732(2) Angstrom, beta=99.24(1)degrees, V=1664.3(4) Angstrom(3), Z=4, D-c=1.388 gcm(-3), MoK alpha(lambda=0.71073 Angstrom), F(000)=716, mu=0.394mm(-1). The structure was solved by direct methods and refined by full matrix least-squares method, and the final crystallographic discrepancy factor is 0.036 for 1884 observed reflections. The molecular backbone is a tricyclic system with the central seven-membered 1,5-diazepine ring in twisted boat-like conformation and cis-fused to both aziridine ring and benzene ring.