4-Benzyl-6,6-dimethyl-morpholine-3-carboxylic acid benzyl ester → 6,6-Dimethylmorpholine-3-carboxylic acid
Reaction equation
C([O:8][C:9]([CH:11]1[CH2:16][O:15][C:14]([CH3:18])([CH3:17])[CH2:13][N:12]1CC1C=CC=CC=1)=[O:10])C1C=CC=CC=1>CC(O)=O.CO.[OH-].[OH-].[Pd+2]>[CH3:17][C:14]1([CH3:18])[CH2:13][NH:12][CH:11]([C:9]([OH:10])=[O:8])[CH2:16][O:15]1Participants
Procedure
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.
Workup
- customThe reaction mixture was purged with hydrogen (balloon)
- additionTo the resulting gray mixture was added 4 ml of water
- dissolutiondissolution
- customThe catalyst was removed by filtration
- concentrationthe filtrate was concentrated to dryness
- customtriturated with EtOAc
- filtrationThe generated white solid was filtered off
- customdried under high vacuum
Sources & evidence
- ORD record
- ord-54a60cd57c1a44bda70269cbfccb447f
- Source dataset
- uspto-grants-2011_05
- Patent number
- US07951801B2
Reaction notes
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