Sodium ethoxide → 5-Bromo-2-(2,6-difluorophenyl)pyrimidine-4-carboxylic acid

関与物質

反応手順

A 2.68 M NaOEt in EtOH solution (3 eq) was added to an ice-bath cooled mixture of 2,6-difluorobenzimidamide hydrochloride (2 eq) in EtOH (0.1 M). The resulting mixture was allowed to warm to rt and stirred under N2 for 30 min. To the reaction mixture was added drop wise a solution of mucobromic acid (1 eq) in EtOH and the reaction was heated in a 50° C. oil bath for 2.5 hr. After cooling to rt the reaction mixture was concentrated in vacuo. H2O and 1.0 N NaOH were added and the aqueous mixture was washed with EtOAc. The aqueous phase was acidified to pH=4 with 1.0 N HCl then extracted with EtOAc. Combined organic extracts were washed once with brine, then dried over anhydrous Na2SO4, filtered, and concentrated in vacuo to give 5-bromo-2-(2,6-difluorophenyl)pyrimidine-4-carboxylic acid. The crude product was used for the next step without further purification. LC/MS (m/z): 316.9 (MH+). LC: Rt: 2.426 min.

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