1,2-Dimethoxyethane → Ethyl 2-(4'-(6-carbamoyl-3,5-dimethylpyrazin-2-yl)-2,2'-dichlorobiphenyl-4-yl)acetate

참여 물질

반응 단계

A solution of 4-(6-carbamoyl-3,5-dimethylpyrazin-2-yl)-2-chlorophenylboronic acid (Intermediate 5-1; 450 mg, 1.47 mmol), methyl 2-(3-chloro-4-(trifluoromethylsulfonyloxy)phenyl)acetate (Intermediate 1-2; 490 mg, 1.47 mmol) and tripotassium phosphate (469 mg, 2.21 mmol) in DME (6 mL), ethanol (3 mL) and water (1.5 mL) was put under vacuum and refilled with nitrogen before addition of (1,1′-bis(diphenylphosphino)ferrocene)-dichloropalladium(II) (DCM adduct) (97 mg, 0.12 mmol). The reaction mixture was heated to and left to stir overnight for 16 hrs. The reaction mixture was allowed to cool to room temperature and then evaporated. The residue was partitioned between water (20 mL) and EtOAc (50 mL). The aqueous was re-extracted with EtOAc (2×10 mL) and the combined organics washed with brine (20 mL), dried (MgSO4) and evaporated to give crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in isohexane on 40 g silicycle column (eluted of at 50%). Pure fractions were evaporated to dryness to afford ethyl 2-(4′-(6-carbamoyl-3,5-dimethylpyrazin-2-yl)-2,2′-dichlorobiphenyl-4-yl)acetate (130 mg, 19.26%) as a white solid. Trans esterification occurred during the reaction giving the product as an ethyl rather than methyl ester.

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