Triethylamine → 3-amino-6-bromo-N'-(3-methylthiophene-2-carbonyl)pyrazine-2-carbohydrazide

Participants

Reaction Steps

To a suspension of 3-amino-6-bromo-pyrazine-2-carboxylic acid (13.26 g, 60.82 mmol) and 3-methylthiophene-2-carbohydrazide (10 g, 60.82 mmol) in DMF (95.00 mL) cooled in an ice bath was added Et3N (7.385 g, 10.17 mL, 72.98 mmol) followed by TBTU (23.43 g, 72.98 mmol) portionwise after complete addition, the reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was diluted with EtOAc (50 mL) and water (50 mL). The layers were separated and the organic extracts washed with water (1×50 mL) and brine (1×50 mL), dried over MgSO4 and concentrated to leave a brown solid (7.85 g, 36% yield) which was used directly in the next step without further purification.

Provenance & Evidence