Pyridine → Ethyl 4-methyl-5-(4-nitrophenyl)-2-(3-phenylureido)thiophene-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

Toluene (500 ml), pyridine (12.27 g, 155.06 mmol) and phenyl isocyanate (14.58 g, 122.41 mmol) were added to ethyl 2-amino-4-methyl-5-(4-nitrophenyl)thiophene-3-carboxylate (25.00 g, 81.61 mmol), and the mixture was stirred at 95-100° C. for 4 hours. It was confirmed that starting materials were almost disappeared. After the reaction solution was stirred for 2 hours under ice-cooling, the crystals were isolated with a centrifuging machine and washed with cold toluene (150 ml). The crystals were dried under vacuum at 60° C. for 8 hours to give ethyl 4-methyl-5-(4-nitrophenyl)-2-(3-phenylureido)thiophene-3-carboxylate (32.42 g, 76.20 mmol, 93.4%)

Provenance & Evidence