Tin tetrachloride → 3-Amino-5-cyclopropylethynylthiophene-2-carboxylic acid methyl ester

Participants

Reaction Steps

Tin chloride (11.8 g) was added to a solution of 5-cyclopropylethynyl-3-nitrothiophene-2-carboxylic acid methyl ester (6.26 g) in ethanol (250 ml), and the reaction mixture was heated to reflux for 4 h. The solvent was then removed in vacuo, and the residue was taken up again in ethyl acetate and washed with sat. Rochelle salt solution. The organic phase was dried over sodium sulfate and the solvent was removed in vacuo. The product with the molecular weight of 221.27 (C11H11NO2S) was obtained in this way; MS (ESI): 222 (M+H+).

Provenance & Evidence