反应详情

A stirred solution of (+/−)-tert-butyl (6-benzyl-6-azaspiro[3.4]octan-8-yl)carbamate (Intermediate 13, 0.523 g, 1.653 mmol) in ethanol (31.2 mL) with Pd/C (10% b/w) (0.418 g, 3.14 mmol) was hydrogenated for 3 hrs 15 min @ 45 psi. +/−MS after 2 hrs 20 min indicated that the reaction was essentially complete (m/e 227.3, M+H for desired product), 171.1 (M+H-isobutylene); no starting material was detected. The catalyst was removed by filtration through a pad of Celite followed by filtration through VWR 0.45 micron Nylon filter disc. The filtrate was concentrated under vacuum, co-evaporated with CH2Cl2, to yield 0.365 g of the title compound as a viscous yellow oil which became a pale yellow solid on standing under vacuum (0.354 g). +/−MS: m/e 227.3 (M+H). 1H NMR (400 MHz, CHLOROFORM-d) δ 4.59 (br. s., 1H), 3.94 (br. s., 1H), 3.23 (dd, J=11.4, 6.2 Hz, 1H), 3.02 (d, J=11.0 Hz, 1H), 2.86 (d, J=11.0 Hz, 1H), 2.68 (dd, J=11.4, 3.7 Hz, 1H), 2.16-2.06 (m, 1H), 2.02-1.80 (m, 5H), 1.77 (d, J=2.9 Hz, 1H), 1.46 (s, 9H).

1. custom+/−MS after 2 hrs 20 min