Urea → 4-(2,2-Dichlorocyclopropyl)phenol

Participants

Reaction Steps

(+)-4-(2,2-Dichlorocyclopropyl)aniline (3 g, 0.015 mol) from the previous resolution was dissolved in concentrated sulphuric acid (15 ml) to which was added iced water (30 ml). With the reaction temperature maintained below 5° C., a solution of sodium nitrite (1.3 g, 0.019 mol) in distilled water (15 ml) was added. After a further 5 minutes, urea (0.27 g, 0.0045 mol) was added to eliminate excess nitrous acid. The pH of the mixture was then adjusted to 3 by addition of an aqueous solution of sodium hydroxide (10M) whilst the temperature of less than 5° C. was maintained. This mixture was then added slowly to a vigorously stirred mixture of cupric nitrate hemipentahydrate (60 g, 0.26 mol) and sodium ascorbate (2.8 g, 0.014 mol) in distilled water (530 ml) and diethyl ether (200 ml). After 5 minutes the organic phase was removed and the aqueous phase extracted with diethyl ether (3× 100 ml). The combined organic phases were washed with distilled water, dried over anhydrous magnesium sulphate and the solvent removed by evaporation under reduced pressure to afford crude (+)-4-(2,2-dichlorocyclopropyl)phenol (3.1 g) which was used directly in the following reaction.

Provenance & Evidence