反应详情

To a solution of 4-benzyl-6,6-dimethyl-morpholine-3-carboxylic acid benzyl ester (Intermediate 18, 1.25 g) in 40 ml of 10% AcOH/MeOH (under nitrogen) was added 250 mg of 20% Pd(OH)2 on charcoal. The reaction mixture was purged with hydrogen (balloon) and was stirred at ambient temperature for 72 hrs. To the resulting gray mixture was added 4 ml of water to help dissolution. The catalyst was removed by filtration and the filtrate was concentrated to dryness. The residue was co-evaporated with ethanol (2×) and then triturated with EtOAc. The generated white solid was filtered off and dried under high vacuum to give 559 mg of 6,6-dimethyl-morpholine-3-carboxylic acid (95% yield). 1H-NMR (300 MHz, D2O): δ 1.35 (s, 3H), 1.38(s, 3H), 3.11 (d, 1H), 3.32 (d, 1H), 3.81-3.87 (m, 1H), 4.05 (bt, 1H), 4.17 (bd, 1H). MS (M+H+): 160.

1. customThe reaction mixture was purged with hydrogen (balloon)
2. additionTo the resulting gray mixture was added 4 ml of water
3. dissolutiondissolution
4. customThe catalyst was removed by filtration
5. concentrationthe filtrate was concentrated to dryness
6. customtriturated with EtOAc
7. filtrationThe generated white solid was filtered off
8. customdried under high vacuum