Diisopropylethylamine → N-[(1-(2-Methanesulphonamidoethyl)-4-piperidyl)methyl] 3,4-dihydro-2H-[1,3]oxazino[3,2-a]indole-10-carboxamide

Participants

Reaction Steps

A stirred solution of N-(4-piperidylmethyl) 3,4-dihydro-2 H-[1,3]oxazino[3,2-a]indole-10-carboxamide (E21, 220 mg, 0.70 mmole) in acetonitrile (8 ml) was treated with diisopropylethylamine (0.24 ml, 1.4 mmole) and N-(2-bromoethyl)methanesulphonamide (D14, 160 mg, 0.77 mmole) and the mixture heated under reflux for 2.5 h. The reaction mixture was concentrated in vacuo and the residue chromatographed on silica gel eluting with dichloromethane/methanol/0.88 ammonia solution (200:10:1). The colourless oil obtained was dissolved in chloroform (30 ml) and washed with water (2×20 ml), then dried (Na2SO4) and concentrated in vacuo. The residue was passed through a short plug of basic alumina eluting with ethyl acetate to afford the title compound as a colourless oil (34 mg, 11%). This was converted to its oxalate salt and crystallised from acetone to give a white solid mp 80°-85° C.

Provenance & Evidence