Benzaldehyde → 5-Benzylidenehydantoin

Participants

Reaction Steps

Similar to the procedure of U.S. Pat. No. 4,345,072, a mixture comprising hydantoin (25 g, 0.25 mole), benzaldehyde (29.3 g, 0.275 mole), ammonium acetate (19.3 g, 0.25 mole) and glacial acetic acid (60 g) were placed in a round bottom flask fitted with stirrer, condenser, thermometer and heating mantle. The white solids became yellow on heating. All the solids dissolved when the temperature reached between 120° C. and 134° C. The mixture was refluxed for one-half hour (125° to 134° C.) and then held at 120° C. for 4 hours with stirring. Solids crystallized out on cooling to room temperature. The solid was suction filtered, water washed and then ethanol washed. After air drying, the yellow orange solid had a weight of 38.0 g for an 81% yield. The melting point of the 5-benzalhydantoin obtained was determined to be 218°-220° C. which corresponds to the melting point reported in BIOCHEM J. 29, 542 (1935).

Provenance & Evidence