Spiro[benzofuran-2(3H),4'-piperidine], 5-broMo- synthesis

Yield:91830-17-0 62%

Reaction Conditions:

with N-Bromosuccinimide in methanol at 0; for 6 h;

Steps:

V.A.101

101. Intermediate 1-5: 5-Bromo-3H-spiro[benzofuran-2,4'-piperidine][00406] To a solution of 1-4 (7.44 g, 39.4 mmol) in methanol at 0⁰C was added N- bromosuccinimide (13.9 g, 78.7 mmol) and the mixture was stirred at 0⁰C for 6 hours. The reaction mixture was concentrated under reduced pressure and the residue was diluted with water and ethyl acetate. The organic layer was separated and the aqueous phase was basified to pH 8 with saturated solution of sodium bicarbonate. The aqueous layer was extracted with ethyl acetate, the combined organic phase were dried over sodium sulfate, the solids were filtered and the filtrate was concentrated to give 1-5 as a brown solid (6 g, 62%). ¹U NMR (400 MHz, CD₃OD) δ: 7.39 (s, 1 H), 7.29 (d, / = 8.4 Hz, 1 H), 6.75 (d, / = 8.4 Hz, 1 H), 3.43-3.40 (m, 4 H), 3.19 (s, 2 H), 2.22-2.19 (m, 2 H), 2.12-2.04 (m, 2 H). MS (ESI): MS (ESI): m/z 268.2, 270 (M+H) ⁺.

References:

WO2010/144571,2010,A1 Location in patent:Page/Page column 128-129