(+/-)-Tert-butyl (6-benzyl-6-azaspiro[3.4]octan-8-yl)carbamate → tert-butyl N-{6-azaspiro[3.4]octan-8-yl}carbamate
Reaction equation
C([N:8]1[CH2:15][CH:14]([NH:16][C:17](=[O:23])[O:18][C:19]([CH3:22])([CH3:21])[CH3:20])[C:10]2([CH2:13][CH2:12][CH2:11]2)[CH2:9]1)C1C=CC=CC=1>C(O)C.[Pd]>[CH2:13]1[C:10]2([CH:14]([NH:16][C:17](=[O:23])[O:18][C:19]([CH3:21])([CH3:20])[CH3:22])[CH2:15][NH:8][CH2:9]2)[CH2:11][CH2:12]1Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
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).
Workup
- custom+/−MS after 2 hrs 20 min
Sources & evidence
- ORD record
- ord-da274cecf42d44d584b661e420e45f54
- Source dataset
- uspto-grants-2015_03
- Patent number
- US08987268B2
Reaction notes
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