3,4-Dichlorophenyl isocyanate → HCID 20335432, compound

Participants

Reaction Steps

The stirred solution of 4.1 g of 1-(p-methoxyphenyl)-3-methyl-2-pyrazolin-5-one in 75 ml of warm benzene and 2.4 g of triethylamine is combined with the solution of 3.8 g of 3,4-dichlorophenylisocyanate in 50 ml of benzene. After standing at ambient temperature for 4 hours, the benzene is evaporated, the residue taken up in methanol and the solution poured into 100 ml of 0.3 N hydrochloric acid. The mixture is allowed to stand overnight at room temperature, the precipitate is collected, washed with water, dried, triturated with benzene-ethyl acetate and recrystallized from methanol to yield the 1-(p-methoxyphenyl)-3-methyl-4-(3,4-dichlorophenylcarbamoyl)-2-pyrazolin-5-one of Formula II with R=OCH3, R'=3--Cl and R"=Cl, melting at 120°-125°, resolidifying and remelting at 228°-232° (dec.).

Provenance & Evidence