4-Toluenesulfonyl chloride → Ethyl 5-(3-amino-6-(4-(isopropylsulfonyl)phenyl)pyrazin-2-yl)-1,3,4-oxadiazole-2-carboxylate

Participants

Reaction Steps

To a stirred solution of ethyl 2-(2-(3-amino-6-(4-(isopropylsulfonyl)phenyl)pyrazine-2-carbonyl)hydrazinyl)-2-oxoacetate (1.1894 g, 2.731 mmol) was in CH2Cl2 (23.78 mL) was added triethylamine (552.7 mg, 761.3 μL, 5.462 mmol), followed by 4-methylbenzenesulfonyl chloride (520.7 mg, 2.731 mmol) and the resulting solution stirred at room temperature for 3 h. The reaction mixture is diluted with CH2Cl2 and washed with water (1×20 mL), saturated aqueous sodium hydrogen carbonate solution (1×20 mL) and brine (1×20 mL). The organic extracts were dried over MgSO4, filtered and concentrated in vacuo. The residue was triturated with acetonitrile to give the product as a yellow solid (1.03 g, 90%); 1H NMR (400 MHz, DMSO) d 1.37 (m, 6H), 1.54 (m, 3H), 3.25 (m, 1H), 4.64 (m, 2H), 8.00 (m, 2H), 8.20 (m, 2H) and 8.83 (s, 1H) ppm; MS (ES+) 418.19

Provenance & Evidence