Sodium Carbonate → 5-(4-{(S)-1-[(S)-6-(2-hydroxy-2-methyl-propyl)-2-oxo-6-phenyl-[1,3]oxazinan-3-yl]ethyl}-phenyl)-pyridine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

2 M aqueous Na2CO3 solution (1.3 mL) was added to a solution of (S)-6-(2-hydroxy-2-methylpropyl)-6-phenyl-3-{(S)-1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-ethyl}-1,3-oxazinan-2-one (0.60 g) and 5-bromo-pyridine-2-carboxylic acid methyl ester (0.41 g) in N,N-dimethylformamide (4 mL). The resulting mixture was sparged with argon for 10 min, before [1,1′-bis(diphenylphosphino)ferrocene]-dichloropalladium(II)dichloromethane complex (61 mg) was added. The mixture was heated to 100° C. and stirred at this temperature overnight. After cooling to ambient temperature, the mixture was diluted with ethyl acetate and extracted with water and brine. The aqueous extracts were combined, acidified (pH ca. 5-6) using citric acid, and extracted with CH2Cl2/MeOH (ca. 10:1). The combined organic extracts were washed with brine and dried (MgSO4). The solvent was removed and the residue was purified by chromatography on silica gel (CH2Cl2/MeOH 98:2→50:50) to afford the title compound as a resin-like solid.

Provenance & Evidence