Reacción #67585

Ecuación de reacción

O-4-nitrobenzoylhydroxylamine

3-tert-butoxycarbonylamino-5-(3,3-dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid methyl ester

→

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

Rendimiento 57.8%

Disolventes

NMP

NMP

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe reaction was quenched with LiCl solution (5% in water, 50 mL)
2. 2
   workup.ADDITIONdiluted with EtOAc (50 mL)
3. 3
   LavadoThe crude product was washed 3×50 mL with 5% LiCl solution
4. 4
   Secadodried over Na2SO4
5. 5
   Otropurified by silica gel chromatography 0-30% EtOAc/hexanes

Procedimiento

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).

Fuente