Crystal structure of methyl 1-methyl-2-oxo-spiro-[indoline-3,2'-oxirane]-3'-carboxyl-ate

In the title compound, C12H11NO4, the dihedral angle between the indole ring system (r.m.s. deviation = 0.019 Å) and the oxirane ring is 88.8 (2)°. The oxirane O atom and the bridging ester O atom are in an approximate syn conformation [O-C-C-O = -25.4 (3)°] In the crystal, inversion dimers linked by pair of C-H⋯O hydrogen bonds generate R 2 (2)(8) loops, where the C-H donor group forms part of the oxirane ring. A second C-H⋯O inter-action arising from one of the C-H groups of the benzene ring links the dimers into [001] double chains.