Triethylamine → HCID 20335441, compound

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Reaction Steps

The suspension of 3.1 g of 1-(p-chlorophenyl)-3-methyl-2-pyrazolin-5-one in 100 ml of benzene is treated with 1.8 g of triethylamine, warmed until dissolution and combined with 2.1 g of p-fluorophenylisocyanate while stirring. After standing overnight at room temperature it is evaporated, the residue taken up in methanol and the solution treated with the mixture of 10 ml of 5 N hydrochloric acid and 250 ml of water. The mixture is extracted with ethyl acetate, the extract washed with water, dried and evaporated. The crude solid is dissolved in 2 N aqueous sodium hydroxide, the solution filtered and acidified with 5 N hydrochloric acid. The precipitate is collected, washed with water and recrystallized from ethyl acetate-petroleum ether, to yield the 1-(p-chlorophenyl)-3-methyl-4-(p-fluorophenylcarbamoyl)-2-pyrazolin-5-one melting at 240°-242° with decomposition.

Provenance & Evidence