Phosphorus oxychloride → 2-Amino-6-chloropurine

Participants

Reaction Conditions

Reaction Steps

A mixture of guanine (22.7 g, 0.15 mol), methyltriethylammonium chloride (TEMAC) (45.5 g, 0.3 mol), phosphorus oxychloride (82.6 ml, 0.9 mol) and acetonitrile (67 ml) was heated at 60° C. with stirring for 6 hours and then cooled to 10° C. The solid material was filtered off and suspended in water (300 mls). The aqueous mixture was brought to alkaline pH with aqueous sodium hydroxide to achieve dissolution and powdered carbon (6.8 g) added. The mixture was stirred for 1 hour and then filtered to remove the carbon. Acetone (72 mls) was added and then the pH reduced to 7 with dilute hydrochloric acid. The product was filtered off, washed with acetone/water (50:50 mixture, 50 mls), water (50 mls), acetone/water (50:50 mixture, 50 mls) and acetone (50 mls) and then dried to give 2-amino-6-chloropurine as a cream coloured solid (14.77 g, 54% yield).

Provenance & Evidence