Ethyl Acetate → 3-Amino-6-bromo-N-(2-morpholinoethyl)-5-(trifluoromethyl)pyrazine-2-carboxamide

Participants

Reaction Steps

To a stirred solution of 3-amino-6-bromo-5-trifluoromethyl-pyrazine-2-carboxylic acid (Intermediate C) (250 mg, 0.874 mmol) in NMP (8 ml) was added 4-(2-aminoethyl)morphonline (138 ul, 1.049 mmol) followed by DIPEA (763 ul, 4.37 mmol). To this solution was then added HATU (499 mg, 1.311 mmol) in portions and the reaction mixture was left to stir at RT for 1 hour. A further 1 equiv. of 4-(2-aminoethyl)morphonline was added. After a further 1.5 hr, 0.5 equiv. HATU (166 mg, 0.425 mmol) was added and the RM was left to stir for a further 30 min. The mixture was added to EtOAc (50 ml) and washed with 0.1 M NaOH (50 ml). The aqueous layer was back extracted with EtOAc (50 ml). The combined organics were washed with water (50 ml), brine (50 ml), dried over magnesium sulfate and evaporated under reduced pressure to give a brown oil (418 mg). The crude product was purified by chromatography (Biotage-silica 20 g/70 ml column, 3:1 EtOAc/iso-hexane). The resulting yellow residue was loaded onto an SCX-2 cartridge (10 g) that had been pre-wetted with MeOH. The cartridge was washed with MeOH (140 ml) and eluted with 3.5M ammonia in methanol solution (70 ml). The appropriate fractions were evaporated under reduced pressure to give a solid. This solid was dissolved in EtOAc and filtered under vacuum. The filtrate was evaporated under reduced pressure and then dried in vacuo to afford the title compound as a yellow solid;

Provenance & Evidence