Dicyclohexylcarbodiimide → 8-Cyclopentyl-3-propyl-3,7-dihydro-purine-2,6-dione

Participants

Reaction Steps

After 30 g (163 mmol) of 5,6-diamino-1-propyl2,4-(lH,3H)-pyrimidinedione (Japanese Published Unexamined Patent Application No. 57517/80) was suspended in 600 ml of N,N'-dimethylformamide, 17.7 ml (163 mmol) of cyclopentanecarboxylic acid, 30.0 g (196 mmol) of hydroxybenztriazole and 50.5 g (245 mmol) of dicyclohexylcarbodiimide were added to the suspension. The mixture was stirred at room temperature overnight. After insoluble materials were filtered off, the filtrate was evaporated under reduced pressure. To the residue was added 600 ml of 4 N sodium hydroxide aqueous solution and the solution was refluxed for 10 minutes under heating. After ice cooling, insoluble materials were filtered off and 50 ml of methanol was added. The resulting mixture was neutralized with conc. hydrochloric acid. The precipitates were collected by filtration to afford 28.3 g (yield, 66%) of Compound c as a white powder.

Provenance & Evidence