Process for synthesis of N-(hydrocarbyl)substituted-p-menthane-3-carboxamide
AssigneePhilip Morris Incorporated
InventorsStephen A. Haut, Roger A. Comes
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Abstract
This invention provides an improved process for synthesizing carboxamides which involves reacting 3-p-menthyl halide with magnesium to form 3-p-menthylmagnesium halide Grignard reagent, and reacting the Grignard reagent with hydrocarbyl isocyanate at a temperature below about -20.degree. C. to form N-hydrocarbyl-p-menthane-3-carboxamide product. The product comprises a mixture of geometric isomers in which the 3-p-menthyl:3-p-neomenthyl weight ratio is at least 4:1 and can be as high as 9:1 under optimal conditions. This invention also provides a novel process for producing acylurea compounds such as N-(3-p-menthylcarbonyl)-N-t-butyl-N'-t-butylurea.
Claims20
A process for the synthesis of N-hydrocarbyl-p-menthane-3-carboxamide which comprises (1) reacting 3-p-menthyl halide with magnesium in an anhydrous solvent medium to form 3-p-menthylmagnesium halide;
- and (2) reacting the 3-p-menthylmagnesium halide with hydrocarbyl isocyanate at a temperature between about -30.degree. C. and -70.degree. C. to form N-hydrocarbyl-p-menthane-3-carboxamide product.
A process for the synthesis of N-hydrocarbyl-p-menthane-3-carboxamide which comprises (1) reacting 3-p-menthyl halide with magnesium in an anhydrous solvent medium to form 3-p-menthylmagnesium halide;
- (2) reacting the 3-p-menthylmagnesium halide with hydrocarbyl isocyanate at a temperature between about -30.degree. C. and -70.degree. C. to form a product mixture comprising N-hydrocarbyl-p-menthane-3-carboxamide and N-(3-p-menthylcarbonyl)-N-hydrocarbyl-N'-hydrocarbylurea;
- and (3) heating the N-(3-p-menthylcarbonyl)-N-hydrocarbyl-N'-hydrocarbylurea in a solvent medium under alkaline pH conditions to produce additional N-hydrocarbyl-p-menthane-3-carboxamide product.
Dependencies are inferred from the claim text.