Lithium hydroxide, monohydrate → 8-[2-((Z)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonylamino]-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 8-[2-((Z)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonylamino]-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylate (Intermediate 20, 0.057 g) and lithium hydroxide monohydrate (0.090 g) in dioxane (4 mL) and water (1 mL) was heated to 80° C. for 32 hours. The resultant mixture was concentrated in vacuo and the residue was acidified with aqueous citric acid solution (10%) and extracted into DCM, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of methanol and DCM with a gradient of 0-15% to give 8-[2-((Z)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonylamino]-5,6-dihydropyrazolo[5,1-a]isoquinoline-7-carboxylic acid (0.020 g) as a white solid.

Provenance & Evidence