Sodium hydride → HCID 70111827, compound

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Reaction Steps

Under N2 atmosphere, 723 mg NaH (60% in oil; 18.1 mmol) is washed twice with hexane, 21 ml DMSO is added, and the mixture heated for 20 min to 70° C. (gas evolution). After cooling to RT, the mixture is diluted with 15 ml DMSO, 6.71 g (17.2 mmol) triphenyl(pyridin-3-yl-methyl)phosphonium chloride (for preparation, see 1a) is added in portions, and the blackish-yellow solution is stirred for 10 min (Wittig reagent). A second flask is prepared with 3.0 g (17.2 mmol) phthalazin-1(2H)-one-4-carbaldehyde in 39 ml DMSO under an inert gas. The above Wittig reagent is added and a little DMSO is then rinsed in. After stirring for 75 min at RT, the mixture is poured onto water/EtOAc, the aqueous phase separated off and extracted again twice with EtOAc. The organic phases are washed with water and brine, combined and extracted twice with 1 N HCl and then discarded. The acidic aqueous phases are immediately adjusted to alkaline pH with sat. Na2CO3 solution and extracted three times with EtOAc. The organic phases are washed with water and brine, dried (Na2SO4) and concentrated by evaporation. This yields the title compound as an E/Z mixture: TLC (EtOAc) Rf=0.18/0.22; HPLC5-40 tR=9.2/9.6; FAB-MS (M+H)+=250.

Provenance & Evidence