Amino 4-nitrobenzoate → 3-(N-tert-butoxycarbonyl-hydrazino)-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester

HRID 39307Notes

Reaction equation

HRID 39307 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].[N+:24](C1C=CC(C(ON)=O)=CC=1)([O-])=O>CN1C(=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])[NH2:24])=[O:4]

Participants

4

Reactant 2

HCID 426419Amino 4-nitrobenzoateHCID 249893453-Tert-butoxycarbonylamino-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester

Product 1

HCID 673210423-(N-tert-butoxycarbonyl-hydrazino)-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl esterYield 57.8%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent2×

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 O-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

  1. customThe reaction was quenched with LiCl solution (5% in water, 50 mL)
  2. additiondiluted with EtOAc (50 mL)
  3. washThe crude product was washed 3×50 mL with 5% LiCl solution
  4. dry with materialdried over Na2SO4
  5. custompurified by silica gel chromatography 0-30% EtOAc/hexanes

Sources & evidence

ORD record
ord-4f765ed62e4446acb9b5137ca15d671b
Source dataset
uspto-grants-2013_09
Patent number
US08524764B2

Reaction notes

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