Dimethyl Sulfoxide → HCID 21217719, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of CH2Cl2 (35 ml) and trifluoroacetic anhydride (3.6 ml, 0.0224 mol) at -78° C. was added CH2Cl2 (5 ml) and DMSO (3.22 ml, 0.0454 mol). The reaction mixture was stirred for 1 hour then a solution of 1-ethyl-6-methoxy-N-(4-hydroxycyclohexyl methyl)-1H-pyrazolo-[3,4-b]quinolin-4-amine (1.8 g, 0.0051 mol) in CH2Cl2 (30 ml) was added and the reaction mixture was slowly warmed to 0° C. with stirring overnight. The reaction mixture was cooled to -78° C. and triethylamine (11 ml, 0.075 mol) was added. The reaction mixture was warmed to room temperature, stirred for 5 hours and then poured into water. The mixture was extracted with CH2Cl2 and the CH2Cl2 extracts were combined, washed with water, dried over MgSO4 and evaporated. The residue was purified by column chromatography on silica gel eluting with ethyl acetate to afford the product as the free base. The free base was dissolved in 2-propanol and methanesulfonic acid was added. The volume was reduced to about 5 ml, ether was added and the precipitated salt was collected by filtration and recrystallized from 2-propanol/ether to afford 1 g of 1-ethyl-6-methoxy-N-[4-oxocyclohexylmethyl]-1H-pyrazolo[3,4-b]quinolin-4-amine.CH3SO3H.1/2 H2O.

Provenance & Evidence