2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → (8R,9R)-8-(tert-butyldimethylsilanyloxy)-2-methyl-9-phenyl-7,8,9,10-tetrahydroimidazo[1,2-h][1,7]naphthyridin-7-one

Participants

Reaction Steps

50.7 g (123.8 mmol) of (8R,9R)-8-(tert-butyldimethylsilanyloxy)-2-methyl-9-phenyl-5,6,7,8,9,10-hexahydroimidazo[1,2-h][1,7]naphthyridin-7-one are treated in portions at 5° C.-10° C. with 35.6 g (153.5 mmol) of 2,3-dichloro-5,6-dicyano-p-benzoquinone. After the end of the addition, the reaction mixture is stirred at room temperature for 2 days. The reaction mixture is extracted with 150 ml of sodium hydroxide solution and the sodium hydroxide solution phase separated off is extracted with 150 ml of toluene and the combined toluene phases are washed with 150 ml of water. The organic phase is concentrated and the residue is dried overnight in a high vacuum. The solid crystallised in this way is stirred in diisopropyl ether, filtered off with suction and dried in vacuo at 50° C. 10.1 g (20% of theory) of the title compound are obtained.

Provenance & Evidence