4-tert-Butylbenzoyl chloride → 4-tert-butyl-N-(7-chloropyrazolo[1,5-a]pyrimidin-5-yl)benzamide

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Reaction Steps

7-Chloropyrazolo[1,5-a]pyrimidin-5-amine 1E (1.0 equivalent) or 7-chloro-2-methylpyrazolo[1,5-a]pyrimidin-5-amine (1J, 1.0 equivalent) was dissolved in anhydrous pyridine (0.35 M). 4-t-Butylbenzoic acid chloride (1.05 equivalents) was added at 0° C., and the mixture was stirred for two hours. The reaction was then quenched with saturated NaHCO3; pyridine was removed in vacuo and the residue was extracted with EtOAc. Combined organic layers were washed twice with 0.2 N HCl to remove residual pyridine, dried over MgSO4, filtered and concentrated. Crude product was purified by column chromatography (SiO2, gradient of 15 to 30% EtOAc/hexanes). The purified product was triturated with Et2O to give 4-tert-butyl-N-(7-chloropyrazolo[1,5-a]pyrimidin-5-yl)benzamide (1F, 47%) or 4-tert-butyl-N-(7-chloro-2-methylpyrazolo[1,5-a]pyrimidin-5-yl)benzamide (1K) of the product as a solid.

Provenance & Evidence