Sulfuric Acid → HCID 57929919, compound

Participants

Reaction Conditions

Reaction Steps

To a round bottom flask was added 3-tert-butyl-6-((2,4-difluorophenyl)ethynyl)-[1,2,4]triazolo[4,3-b]pyridazine (4.20 g, 13.5 mmol, Example #9, Step D) and concentrated H2SO4 (50 mL, 560 mmol). The reaction mixture was heated to about 90° C. for about 2 h. The reaction mixture was quenched with ice (500 g) and extracted with DCM (500 mL). The aqueous layer was neutralized to pH of about 7.0 with solid NaOH and additional ice (1000 g) was added to maintain a temperature of about 0-10° C. The aqueous layer was extracted with DCM (3×200 mL). The combined organic extracts were dried over Na2SO4, filtered and concentrated in vacuo. The crude material was purified by silica gel chromatography using MeOH/DCM (10:90) to give the title compound (4.4 g, 99%) as a solid. LC/MS (Table 1, Method a) Rt=3.20 min; MS m/z: 331.1 (M+H)+.

Provenance & Evidence