Formaldehyde → 1,1-Dimethylethyl (2R,6S)-2,6-dimethyl-4-{[4-(methylamino)phenyl]methyl}-1-piperazinecarboxylate
Reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][N:9]2[CH2:14][C@H:13]([CH3:15])[N:12]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[C@H:11]([CH3:23])[CH2:10]2)=[CH:4][CH:3]=1.[BH4-].[Na+].[CH2:26]=O.C[O-].[Na+]>>[CH3:23][C@@H:11]1[CH2:10][N:9]([CH2:8][C:5]2[CH:6]=[CH:7][C:2]([NH:1][CH3:26])=[CH:3][CH:4]=2)[CH2:14][C@H:13]([CH3:15])[N:12]1[C:16]([O:18][C:19]([CH3:21])([CH3:20])[CH3:22])=[O:17]Participants
Reactant 4
Product 1
Conditions
- Temperature
- 50 °C
Procedure
The title compound was prepared from 1,1-dimethylethyl (2R,6S)-4-[(4-aminophenyl)methyl]-2,6-dimethyl-1-piperazinecarboxylate (D28) using a method similar to that described for D23 in Description 23A although the reaction was heated at 50° C. for 48 h prior to addition of sodium borohydride then for 1 h after addition. Further paraformaldehyde (1 eq) and sodium methoxide (1 eq) were added; the reaction was heated at 50° C. for 12 h; further sodium borohydride (1 eq) was added and the reaction heated at 50° C. for 1 h. δH (CDCl3, 400 MHz) 7.16 (2H, d), 6.57 (2H, d), 4.05 (2H, m), 3.70 (1H, br s), 3.36 (2H, s), 2.82 (3H, s), 2.59 (2H, d), 2.06 (2H, dd), 1.49 (9H, s), 1.27 (6H, d). MS (ES): 356.3, (MNa+), 234.3, no molecular ion (MH+) observed.
Workup
- additionfor 1 h after addition
- temperaturethe reaction was heated at 50° C. for 12 h
- temperaturethe reaction heated at 50° C. for 1 h. δH (CDCl3, 400 MHz) 7.16 (2H, d), 6.57 (2H, d), 4.05 (2H, m), 3.70 (1H, br s), 3.36 (2H, s), 2.82 (3H, s), 2.59 (2H, d), 2.06 (2H, dd), 1.49 (9H, s), 1.27 (6H, d)
Sources & evidence
- ORD record
- ord-ec0c4604408e431ab55b870250afbc12
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08012981B2
Reaction notes
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