Diisopropylamine → 1H-Pyrazole-4-carboxylic acid, 3-(4-chlorophenyl)-1-(((4-chlorophenyl)amino)carbonyl)-4,5-dihydro-4-methyl-, methyl ester

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Reaction Steps

To 3.1 g of diisopropylamine dissolved in 15 ml of tetrahydrofuran and cooled in an ice salt bath was added 8.0 ml of a 2.7 molar solution of n-butyllithium in hexane. After stirring for 5 minutes a solution of 3.4 g of N,3-bis-(4-chlorophenyl)-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide in 7 ml of tetrahydrofuran was added and the resulting solution stirred for 15 minutes. To this solution was added 1.5 ml of dimethylcarbonate and, after 15 minutes 1.5 ml of acetic acid was added. The reaction mixture was partitioned between diethyl ether and water and the organic layer was dried over anhydrous magnesium sulfate. The resulting solution was filtered and evaporated in vacuo to give 3.0 g of N,3-bis-(4-chlorophenyl)-4-carbomethoxy-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide, mp 122° C. NMR and IR data were consistent with the structure.

Provenance & Evidence