Ethanolamine → 5-[(3,4-Dihydroxyphenyl)methylidene]imidazolidine-2,4-dione

Participants

Reaction Steps

A mixture of 3,4-dihydroxybenzaldehyde (2.072 g.) and hydantoin (1.50 g.) in water (15 ml) was heated to 70° to give a clear solution. To this was added monoethanolamine (1.38 g.) and the magnetically stirred mixture was heated (90°-92°, bath temperature) for 4 hours. Within 10 minutes crystallization occurred. The product was allowed to cool to room temperature and was stored overnight. After immersing in an ice-bath, the mixture was acidified with HCl, refrigerated 5 hours, filtered, washed with cold (-10° C) 1:1 methanol-water and dried. The title compound was obtained as a pale brown solid: 2.776 g, m.p. 300°-310°. (Trituration with hot absolute ethanol gave a pale brown solid in ca 65% recovery, m.p. 320° decomp.)

Provenance & Evidence