Dimethylformamide → 2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one

Participants

Reaction Conditions

Reaction Steps

To a 10-mL reaction vial was added 5-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-N-(2-chloroethyl)-1H-pyrazole-3-carboxamide (471a) (82 mg, 0.21 mmol), K2CO3 (88 mg, 0.64 mmol), DMF (1 mL), and ACN (1 mL). The vial was closed and the reaction mixture was heated at 85° C. for 5 h. The reaction mixture was cooled to RT and partitioned between water (5 mL) and EtOAc (5 mL). The organic extract was taken and washed with brine (10 mL), dried over Na2SO4, and concentrated. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (12 g), eluting with a gradient of 0-3% 2 M NH3/MeOH in DCM to provide 2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (471) (26 mg, 35% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 13.51 (s, 1H), 7.86 (dd, J=1.27, 7.34 Hz, 1H), 7.75 (dd, J=1.08, 7.92 Hz, 1H), 7.36-7.42 (m, 2H), 6.07 (s, 1H), 4.36 (t, J=9.49 Hz, 2H), 3.90-3.97 (m, 2H), 2.56 (s, 3H), 1.51 (s, 9H). m/z (ESI, +ve) 351.0 (M+H)+.

Provenance & Evidence