p-Toluenesulfonic acid monohydrate → 1-Cyclohexyl-5-[2-methoxy-4-(1-methyl-1,2,3,6-tetrahydro-4-pyridinyl)phenyl]-3-methyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

Participants

Reaction Steps

To a 10 ml toluene solution of 160 mg (0.35 mmol) of the compound obtained in Example 122, 135 mg (0.71 mmol) of p-toluenesulfonic acid monohydrate was added, and the mixture was heated under reflux for 22 hours with the use of a Dean-Stark dehydrator. The reaction mixture was returned to room temperature, and washed with a saturated aqueous solution of sodium hydrogen carbonate. The system was dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (chloroform/methanol=30/1) to obtain 78 mg (51%) of the captioned compound.

Provenance & Evidence