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