6,6-dimethyl-1,5,7-trioxaspiro[2.5]octane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 6,6-Dimethyl-1,5,7-trioxaspiro[2.5]octane (292 mg, 2.03 mmol) prepared according to a known method described in publications (EP227338, for example) and the 7-amino-3-(2-trifluoromethylphenyl)-2H-isoquinolin-1-one (154 mg, 0.506 mmol) obtained in step C of Example 1-1 were dissolved in ethanol (4 ml). The obtained mixture was stirred at a room temperature for 4 hours and then stirred under heating to reflux for 18 hours. Thereafter, lithium bromide (0.2 mg, mmol) was added to the reaction solution at a room temperature, and the obtained mixture was then stirred for 3 hours. Thereafter, the reaction solution was concentrated, and water was then added thereto, followed by extraction with ethyl acetate. The extract was washed with water and a saturated saline solution, and was then dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure. The obtained residue was purified by silica gel column chromatography (methylene chloride:methanol=40:1 to 20:1), so as to obtain 7-[(5-hydroxy-2,2-dimethyl-[1,3]dioxan-5-ylmethyl)amino]-3-(2-trifluoromethylphenyl)-2H-isoquinolin-1-one (163 mg, 72%). stirred under heating to reflux for 18 hours the obtained mixture was then stirred for 3 hours Thereafter, the reaction solution was concentrated water was then added followed by extraction with ethyl acetate The extract was washed with water a saturated saline solution, and was then dried over anhydrous sodium sulfate The solvent was distilled away under reduced pressure The obtained residue was purified by silica gel column chromatography (methylene chloride:methanol=40:1 to 20:1)