Isopropanol → 6-(tert-butyl)-2-(3-chloro-2-(hydroxymethyl)phenyl)-8-fluorophthalazin-1(2H)-one

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Reaction Steps

2-(6-tert-Butyl-8-fluoro-1-oxo-1H-phthalazin-2-yl)-6-chloro-benzaldehyde (125 g, 0.35 mol) was dissolved in DCM (1 L) with stirring at room temperature, and then 0.5 L of IPA was added to the solution. The resulting solution was cooled down to 4° C., and NaBH4 (5.9 g, 0.16 mol) was added portion wise. After 30 min stirring, the reaction was quenched by adding H2O (200 mL). The organic layer was collected by phase separation, and DCM was distilled out from the solution with adding additional IPA (1.6 L) in the same time at about 80° C. The desired product started to crystallize out from IPA at around 30° C. with seeding, then water (750 mL) was added to the solution dropwise. The resulting solution was cooled down to 5° C. and filtered to collect the crystal material. The filter cake was washed with IPA/water (2/1, 450 mL, pre-cooled to 5° C.), and dried under vacuum oven at 65° C. overnight to afford 82.3 g of the title compound (65.5% isolated yield) as a white solid. MS (ESI) 360, 362 (M+H)+.

Provenance & Evidence