Diethyl Oxalate → HCID 21544772, compound

Participants

Reaction Steps

A mixture of 1-(2-acetyl-3-hydroxyphenoxy)-2-hydroxy-3-p-bromophenoxypropane (15.2 g) and diethyl oxalate (15 ml) was added to a suspension of sodium ethoxide (prepared from 3.0 sodium) in absolute ether. The mixture was heated under reflux for 1.5 hours and then poured onto ice (100 g). After acidification with a solution of acetic acid (12 ml) in water (80 ml), the ether layer was separated and the aqueous layer was extracted with ether (3 × 25 ml). The combined ether solutions were evaporated and the residue was dissolved in a mixture of acetic acid (80 ml) and hydrochloric acid (30 ml) and heated under reflux for 1 hour. Recrystallization from acetic acid yielded crude 1-(2-carboxychromon-5-yloxy)-2-hydroxy-3-p-bromophenoxypropane, (14.7 g), as a white solid, m.p. 188°-190°, which was converted to the ethyl ester employing absolute ethyl alcohol and concentrated sulphuric acid as catalyst. 1-(2-carbethoxychromon-5-yloxy)-2-hydroxy-2-p-bromophenoxypropane was obtained as white crystals, m.p. 79°-80° after recrystallization from aqueous dioxane.

Provenance & Evidence