Butyl isocyanate → N-(Butylcarbamoyl)-3-methylthiophene-2-sulfonamide

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Reaction Steps

To 150 ml of acetone and 3-methyl-2-thiophenesulfonamide was added 11 g of n-butyl isocyanate and 14 g of anhydrous potassium carbonate. After stirring at ambient temperature for 24 hours, the mixture was concentrated to 2/3 of its volume and poured into ice-water. The pH was adjusted to 3 by the addition of hydrochloric acid and the solid thus obtained was filtered, air dried and triturated with 1-chlorobutane to yield 10.6 g of N-(butylaminocarbonyl)-3-methyl-2-thiophenesulfonamide melting at 144°-146°. It showed absorption peaks by NMR (60 MC) at 2.6 δ (singlet, CH3), 1-1.8 δ (mult., C3H7), 3.42 δ (trip., N--CH2 --of butyl) and at 7.1 δ and 7.7 δ (2 doublets for CH's of thiophene) consistent for the desired structure.

Provenance & Evidence