2-Bromo-4-fluorobenzene-1-sulfonyl chloride → Methyl 8-(2-bromo-4-fluorobenzenesulfonylamino)-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylate

Participants

Reaction Steps

A mixture of methyl 8-amino-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylate (Intermediate 22, 0.060 g) and 2-bromo-4-fluorobenzenesulfonyl chloride (0.081 g) in pyridine (2 mL) and DCM (4 mL) was stirred at room temperature overnight. A further amount of 2-bromo-4-fluoro-benzenesulfonyl chloride (0.010 g) was added and the reaction mixture was stirred at room temperature for 2 hours. The resultant mixture was concentrated in vacuo and the residue was dissolved in DCM and washed with 1M hydrochloric acid, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-100% to give methyl 8-(2-bromo-4-fluorobenzenesulfonylamino)-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylate (0.088 g) as a glass.

Provenance & Evidence