Ethyl orthoformate → HCID 18651641, compound

Participants

Reaction Conditions

Reaction Steps

Under nitrogen atmosphere, N-{4-chloro-5-formamido-6-[(1R,4S)-4-(hydroxymethyl)cyclopent-2-enylamino]pyrimidin-2-yl}isobutyramide (15 mg, 42.4 mmol) was dissolved in an anhydrous solution of isopropanol/HCl 1 N (254 ml, 254.4 mmol) and heated to 40-42° C. for 3.5 h. The solution was cooled to 5/10° C. and triethyl orthoformate (21 ml, 127.2 mmol) was added. The resulting mixture was stirred for 2 h at 5-10° C. NaHCO3 (21.37 g, 254.4 mmol) was added slowly, stirred 30 min and the salts were filtered off. To the resulting clear solution, NaHCO3 (3.56 g, 42.4 mmol) and cyclopropylamine (14.7 ml, 212 mmol) were added, the mixture was refluxed for 1 h and the salts were filtered off. The solution was evaporated and the syrup was dissolved in hot isopropanol (120 ml). This mixture was cooled to 0-2° C. and the resulting slurry filtered off. The solid was dried under vacuum at 30° C. There was obtained 10.97 g (73%) of (−)-N-{6-(cyclopropylamino)-9-[(1R,4S)-4-(hydroxymethyl)cyclopent-2-enyl]-9H-purin-2-yl}isobutyramide as a white powder. HPLC analysis: 95.0%+3.8% Abacavir.

Provenance & Evidence