Triethylamine → 4-[4-(Hydroxyaminocarbonyl)methoxy-3,5-dimethyphenyl]-2-methyl-1(2H)phthalazinone

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Reaction Steps

A solution of example 108 (1.15 g) in dichloromethane (30 ml) at 0° C. was treated with triethylamine (0.52 g) followed by isopropenyl chloroformate (0.41 g), and the mixture was stirred for 1 h. O-tert-butyldimethylsilylhydroxylamine (0.50 g) was then added and the mixture was stirred for a further 18 h. The reaction mixture was washed with 10% citric acid (20 ml), saturated sodium bicarbonate (20 ml) and the concentrated to dryness in vacuo. A solution of the residual solid in tetrahydrofuran (30 ml) and water (5 ml) was then treated with a 1.0 M solution of tetrabutylammonium fluoride in tetrahydrofuran (1 ml) and stirred 1 h. the resultant crude mixture was concentrated on to silica and purified by chromatography, eluting with 5% methanol in dichloromethane, to provide the title compound as a white solid (0.10 g).

Provenance & Evidence