Thionyl Chloride → Cyclohexanecarbonyl chloride, 5-methyl-2-(1-methylethyl)-

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Reaction Steps

The preparation of N-substituted-aryl-alkylcarboxamides is familiar to practitioners of the art of chemistry and, for example, is described in U.S. Pat. No. 4,193,936. Starting with the corresponding alkanoyl chloride, a single step reaction with the appropriate amine yields the desired product. For example, an alicyclic compound, p-menthane-3-carboxylic acid (synonym: 2-isopropyl-5-methylcyclohexanecarboxylic acid) is reacted with thionyl chloride in diethylether to yield the p-menth-3-oyl chloride which, when stirred with the substituted-arylamine at room temperature for about 4 hr, generates the corresponding N-substituted-aryl-p-menthane-3-carboxamide. The precipitated product is readily collected by filtration and may be recrystallized using solvents such ethyl acetate or purified on silica gel columns. The final products are solids stable at room temperature. The arylamine may, for example, be 3-methyl-4-iodo-phenylamine, or 4-fluorophenylamine, or 4-iodo-1-naphthylamine and the corresponding product after reaction with p-menth-3-oyl chloride would be N-(3′-methyl-4′-iodo-phenyl)-2-isopropyl-5-methylcyclohexane-3-carboxamide, N-(4′-fluorophenyl)-2-isopropyl-5-methylcyclohexane-3-carboxamide, and N-(4′-iodo-1′-naphthyl)-2-isopropyl-5-methylcyclohexane-3-carboxamide respectively.

Provenance & Evidence