tert-butyl 3-(7-hydroxypyrazolo[1,5-a]pyrimidin-5-yl)piperidine-1-carboxylate synthesis

Yield:891494-66-9 73%

Reaction Conditions:

in toluene; for 24 h;Product distribution / selectivity;Heating / reflux;

Steps:

2; X-20-C

A mixture of the beta-ketoester from Preparative Example 1 (20.0 g, 70.1 mmol) and 3-aminopyrazole (5.40 g, 65.0 mmol) in anhydrous toluene (60 mL) was stirred and refluxed under N₂ for 24 hr. The solvent was evaporated and the residue was purified by column chromatography on silica gel with 20:1 CH₂Cl₂/MeOH as eluent. White solid (15.0 g, 73%) was obtained. LC-MS: 319 [M+H].; PREPARATIVE EXAMPLE X-20-C A mixture of the beta-ketoester from Preparative Example X-10-C (20.0 g, 70.1 mmol) and 3-aminopyrazole (5.40 g, 65.0 mmol) in anhydrous toluene (60 mL) was stirred and refluxed under N₂ for 24 hr. The solvent was evaporated and the residue was purified by column chromatography on silica gel with 20:1 CH₂Cl₂/MeOH as eluent. White solid (15.0 g, 73%) was obtained. LC-MS: 319 [M+H].

References:

US2007/82900,2007,A1 Location in patent:Page/Page column 95; 113