p-Toluenesulfonic acid → HCID 90418372, compound

Participants

Reaction Conditions

Reaction Steps

Into a 100-mL round-bottom flask, was placed ethyl 2-amino-4-hydroxy-5-methyl-4-(trifluoromethyl)-4,5-dihydrothiophene-3-carboxylate (5.7 g, 21.01 mmol, 1.00 equiv), dichloromethane (20 mL), 4-methylbenzene-1-sulfonic acid (3.6 g, 20.91 mmol, 0.99 equiv). The resulting solution was stirred overnight at 25° C. The solids were filtered out. The filtrate was concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (40/60). The collected fractions were combined and concentrated under vacuum. This resulted in 3.95 g (71%) of ethyl 2-amino-5-methyl-4-(trifluoromethyl)thiophene-3-carboxylate as yellow oil.

Provenance & Evidence