Hydrochloric Acid → 5-Methyl-4-phenylacetylamino-thiophene-2-carboxylic acid benzyl ester

Participants

Reaction Steps

Phenylacetyl chloride (0.26 g, 1.7 mmol) was added to a stirred solution of 5-methyl-4-amino-thiophene-2-carboxylic acid benzyl ester (0.4 g, 1.6 mmol), prepared as described above in Step 2, and diisopropylethylamine (0.26 g, 2.0 mmol) in tetrahydrofuran (15 mL) under an inert atmosphere at room temperature. After 18 hours, the mixture was diluted with water (100 mL) and acidified with aqueous HCl. The precipitate was filtered off, rinsed with water, then ethanol, then ether, and dried to afford 0.3 g of 5-methyl-4-phenylacetylamino-thiophene-2-carboxylic acid benzyl ester. Recrystallization of a sample from acetonitrile gave product with a mp 173-174° C.

Provenance & Evidence