Hydrochloric Acid → HCID 20161347, compound

Participants

Reaction Steps

To a mechanically stirred suspension of 5-[N-(2-oxo-1,2,5,6-tetrahydropyridin-4-yl)]amino-1-(2-chloroethyl)-4-cyanopyrazole (12.31 g.) in dry methylene chloride (100 ml.) under a nitrogen atmosphere at 0° was added slowly trimethylaluminum (68.64 ml. of a 1.35 M solution in heptane). There was a vigorous gas evolution. The resulting yellowish sludge was warmed to room temperature and stirred for one hour. EtOAc was added, the yellow solution was cooled to 0° , and enough 10% v/v aqueous hydrochloric acid was cautiously added to bring the pH to 4 (about 15 ml.). The reaction mixture was stirred overnight (17 hours). 10% w/v Aqueous sodium hydroxide solution (500 ml.) was added and the mixture stirred for three hours, followed by extraction several times into EtOAc/MeOH (9:1 v/v). The extracts were washed with brine, dried over magnesium sulfate, filtered through diatomaceous earth and concentrated to an off-white solid. Chromatography using silica gel with acetone/ methylene chloride (1:1 v/v) as eluant gave 4-amino-1-(2-chloroethyl)-7,8-dihydro-1H-pyrazolo[3,4-b][1,6]-napthyridin -5(6H)-one as a white solid (8.89 g.) (72% yield).

Provenance & Evidence