Formaldehyde → HCID 178482103, compound

Participants

Reaction Steps

To a solution of 0.20 g (0.32 mmol) of tert-butyl 6-(4-amino-2-fluorophenyl)-4-(4-(4-(tert-butoxycarbonyl)piperazin-1-yl)phenyl)-5-cyano-3-methyl-1H-pyrazolo[3,4-b]pyridine-1-carboxylate in 40 ml of MeOH are added 0.16 mg (2.9 mmol) of sodium methoxide and 0.10 g (3.2 mmol) of paraformaldehyde. The reaction mixture is refluxed for 2 h. The mixture is then cooled, 0.24 g (6.34 mmol) of sodium borohydride is added, and the mixture is refluxed for 1 h. The mixture is then cooled, diluted with iced water, then extracted with dichloromethane. The organic phase is dried over magnesium sulfate, filtered, and concentrated. The solid obtained is then purified by chromatography on silica (methanol gradient in dichloromethane: 1 to 2%) to give 0.036 g (18%) of tert-butyl 4-(4-(5-cyano-6-(2-fluoro-4-(methylamino)phenyl)-3-methyl-1H-pyrazolo[3,4-b]pyridin-4-yl)phenyl)piperazine-1-carboxylate in the form of yellow crystals. Deprotection of the piperazine following general procedure E2 gives 0.02 g (68%) of 6-(2-fluoro-4-(methylamino)phenyl)-3-methyl-4-(4-(piperazine-1-yl)phenyl)-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile hydrochloride in the form of orange crystals.

Provenance & Evidence