Diethyl (ethoxymethylene)malonate → 2-[5-{2,2-Bis(ethoxycarbonyl)-vinylamino}-2-propoxyphenyl]-8-azapurin-6-one

Participants

Reaction Conditions

Reaction Steps

A suspension of 2-(5-amino-2-propoxyphenyl)-8-azapurin-6-one (1.43 g) in dry sulpholane (15 ml) was treated with diethyl ethoxymethylenemalonate (1.25 g). The mixture was then stirred at 140° C. for one hour, under a slight vacuum in order to remove ethanol. After cooling, the mixture was poured with stirring into dilute hydrochloric acid (150 ml; 2 N), to give a buff-coloured gum which, on scratching, crystallised. Recrystallisation twice from a mixture of dimethylformamide and water, with the aid of charcoal, gave 2-[5-{2,2-bis(ethoxycarbonyl)-vinylamino}-2-propoxyphenyl]-8-azapurin-6-one (1.3 g), m.p. 226°-227° C.

Provenance & Evidence