4-Fluorophenyl isocyanate → 1-Methyl-beta-oxo-alpha-(p-fluorophenylcarbamoyl)-2-pyrrolpropionitrile

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Reaction Steps

To the suspension of 4.0 g of 1-methyl-β-oxo-2-pyrrolpropionitrile in 70 ml of toluene and 3.2 g of triethylamine, 3.7 g of p-fluorophenylisocyanate are added while stirring. The mixture is warmed on the steam cone until dissolution and the red-brown solution is allowed to stand overnight at room temperature. It is evaporated on the steam cone, the residue taken up in methanol and the solution poured into the mixture of 8 ml of 5 N hydrochloric acid and 300 ml of water. The precipitated crystals are collected, washed with water, dried, triturated with methanol and recrystalllized from ethyl acetate, to yield the 1-methyl-β-oxo-α-(p-fluorophenylcarbamoyl)-2-pyrrolpropionitrile melting at 198°-199°.

Provenance & Evidence