Methanol → Methyl 2-oxospiro[indoline-3,4'-piperidine]-5-carboxylate hydrochloride

Participants

Reaction Steps

To a solution of 1′-(tert-butoxycarbonyl)-2-oxospiro[indoline-3,4′-piperidine]-5-carboxylic acid (2 g, 6.0 mmol) in methanol (30 mL) was added dropwise SOCl2 (5 mL) at 0° C. Then the reaction mixture was stirred overnight at rt. The reaction mixture was concentrated to give methyl 2-oxospiro[indoline-3,4′-piperidine]-5-carboxylate hydrochloride (1.4 g, 81%), which was used for the next step without purification. 1H NMR (CD3OD): 2.00 (m, 2H), 2.20 (m, 2H), 3.281 (m, 1H), 3.39 (m, 2H), 3.61 (m, 2H), 3.85 (m, 2H), 3.88 (m, 2H), 7.00 (m, 1H), 7.98 (m, 2H).

Provenance & Evidence