Methyl 3-amino-2-thiophenecarboxylate → Methyl 3-nitrothiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of methyl 3-aminothiophene-2-carboxylate (5 g, 31.8 mmol) in Conc. HCl (4.77 ml) was added aq. solution of sodium nitrite (2.195 g, 31.8 mmol) slowly at 0-5° C. Reaction mixture was stirred at 0-5° C. for 1 h. To this was added aq. solution of sodium tetrafluoroborate (5.24 g, 47.7 mmol) in one lot. After 30 min. precipitated product was filtered. The product was added to the stirring suspension of copper bronze (6.06 g, 95 mmol) and sodium nitrite (26.3 g, 382 mmol) in water (100 ml). Reaction mixture was stirred at 25° C. for 1 h. Reaction mixture was diluted with water and EtOAc and filtered through Hyflow bed. The organic layer was separated and distilled out to get crude product which was column purified using 0-5% EtOAC in hexane to get titled compound as light yellow solid in 63% yield.

Provenance & Evidence