Crystal structure of 1,2-bis-(4-bromophenyl)-3,5-dimethyl-4-oxo-6,7-diazabicyclo[3,2,0]hept-2-ene-6,7-dicarboxylate

Abstract

Crystals of the title compound (Ib) are monoclinic with Z= 4 in a unit cell of dimensions a= 12·395 b= 15·527, c= 11·773 Åβ= 92·8° space group P2₁/n. The structure was solved from diffractometer data by Patterson and Fourier methods and refined to R 0·071 for 1959 independent reflections. Atoms of the four-membered ring are displaced from a least-squares plane by ±0·057 Å. The two planes for the two triangles CNN and CCN intersect at 172·9°. The five-membered ring is planar (maximum displacement 0·023 Å) and is buckled with respect to the four-membered ring the dihedral angle being 112°. The two phenyl rings are tilted at angles of 58·4 and 86·2° with respect to the five-membered ring. The mean planes of the two phenyl rings intersect at 66·4°. The two Br–C(Ph) distances are 1·893(13) and 1·940(12)Å. Interatomic distances in the four-membered ring are: C–C 1·582(17) C–N 1·550(14) and 1·529(15) and N–N 1·467(14)Å. Bond distances for the ester groups at position 6 and 7 are: N–C 1·432(17) and 1·386(18) CO 1·160(16) and 1·186(19) C–O 1·375 and 1·350 and O–C(Me) 1·511(17) and 1·452(18)Å.