Triethylamine → 2-Bromo-N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-3-methoxythiophene-4-carboxamide

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Reaction Steps

2-Bromo-3-methoxythiophene-4-carboxylic acid (0.429 g; 1.81 mmol) was heated at reflux in thionyl chloride (8 ml) for 1 hour, cooled, evaporated in vacuo and the residue azeotroped with toluene. The orange residue was redissolved in CH2Cl2 (5 ml) and treated with dry triethylamine (0.25 ml;1.81 mmol) and 4-methoxy-3-(4-methyl-1-piperazinyl)benzenamine (0.4 g; 1.8mmol). The solution was stirred under Ar (18 hours), evaporated in vacuo and partitioned satd. K2CO3 (aq)/EtOAc. The organic phases were combined, dried over Na2SO4, filtered and the filtrate evaporated in vacuo to a brown gum. The gum was purified by flash silica-gel chromatography and eluted with 2%MeOH/CHCl3 to yield the title compound as white powder after trituration with Et2O (0.43 g;54%), mp=120-122° C.

Provenance & Evidence