Acetyl chloride → 1-(5-Acetylthiophen-2-yl)propan-2-yl 4-methylbenzene-1-sulfonate

Participants

Reaction Steps

2-(p-Toluenesulphonyloxy)propylthiophene (J. Org. Chem. 36, 1971, 2236) was reacted with acetyl chloride and aluminium trichloride in methylene chloride to give 5-acetyl-2-(p-toluenesulphonyloxy)propylthiophene. Therefrom there was obtained with sodium azide in dimethyl sulphoxide 5-(3-azidopropyl)-2-thienyl methyl ketone. Oxidation with hypobromide gave 5-(3-azidopropyl)-2-thiophenecarboxylic acid of melting point 71°-72°. Reaction of this acid with thionyl chloride and subsequent treatment with concentrated ammonia gave 5-(3-azidopropyl)-2-thiophenecarboxamide of melting point 85°-87°. Therefrom there is obtained, after treatment with triphenylphosphine and hydrolysis (J. Org. Chem. 40, 1975, 1659), 5-(3-aminopropyl)-2-thiophenecarboxamide of melting point 143.5°-144° (from water).

Provenance & Evidence