N-methyl-2-pyrrolidone → 3-(N-tert-butoxycarbonyl-hydrazino)-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:18]#[C:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[CH:8][C:9]=1[NH:10][C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])=[O:4].C[N:25]1C(=O)CCC1>>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:18]#[C:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[CH:8][C:9]=1[N:10]([C:11]([O:13][C:14]([CH3:15])([CH3:16])[CH3:17])=[O:12])[NH2:25])=[O:4]Participants
3
Procedure
To a solution of 3-tert-butoxycarbonylamino-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester (4.3 g, 12.8 mmol) in NMP (64 mL) was added K-OtBu (1.6 g, 14.1 mmol). After 10 min a solution of 0-4-nitrobenzoylhydroxylamine (3.0 g, 16.6 mmol) in NMP (16 mL) was added dropwise and the reaction was allowed to stir for 16 h. The reaction was quenched with LiCl solution (5% in water, 50 mL) and diluted with EtOAc (50 mL). The crude product was washed 3×50 mL with 5% LiCl solution, dried over Na2SO4, and purified by silica gel chromatography 0-30% EtOAc/hexanes to give 3-(N-tert-butoxycarbonyl-hydrazino)-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester (2.6 g, 7.4 mmol).
Workup
- customThe reaction was quenched with LiCl solution (5% in water, 50 mL)
- additiondiluted with EtOAc (50 mL)
- washThe crude product was washed 3×50 mL with 5% LiCl solution
- dry with materialdried over Na2SO4
- custompurified by silica gel chromatography 0-30% EtOAc/hexanes
Sources & evidence
- ORD record
- ord-f4f138f2cf964bdb82700800dcbc8b76
- Source dataset
- uspto-grants-2014_11
- Patent number
- US08884030B2
Reaction notes
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