Trifluoroacetic acid → 5-Cyclohex-1-enyl-3-aminothiophene-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-tert-butoxycarbonylamino-5-(1-hydroxy-cyclohexyl)-thiophene-2-carboxylic acid methyl ester (68 g, 0.192 mol) in 400 mL of dichloromethane at 0° C. (ice bath) was added trifluoroacetic acid (400 mL). The mixture was stirred for 30 min at 0° C. and followed by TLC. After completion, the reaction mixture was evaporated to dryness and partitioned between ethyl acetate and saturated water solution of NaHCO3. The organic layer was separated, dried (Na2SO4) and concentrated. The residue was triturated in 4.4 volume of hexane for 30 min. Then filtered and washed with cold hexane. Dried in the vacuum oven to afford 35 g (76%) of 3-Amino-5-cyclohex-1-enyl-thiophene-2-carboxylic acid methyl ester.

Provenance & Evidence