Azobisisobutyronitrile → 7'-bromo-2'-ethyl-6',9',11'-trihydroxyspiro[1,3-dioxolane-2,1'-7,8,9,10-tetrahydro-2H-tetracene]-5',12'-dione

Participants

Reaction Steps

9-(1,1-Ethylenedioxy)ethyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione (10.0 g) was dissolved in a mixture of chloroform (395 ml), carbon tetrachloride (980 ml) and water (890 ml) while heating, azobisisobutyronitrile (2.0 g) and bromine (8.0 g) were added thereto in order, and the resultant mixture was stirred under reflux for 1.5 hours. The reaction mixture was stirred in an ice bath for 1 hour, and the precipitated red orange crystals were collected by filtration, washed with water and dried under reduced pressure to give the crude product of 7-bromo-9-(1,1-ethylenedioxy)ethyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione. M.P., 196°-235° C.; IR (Nujol) ν cm-1 : 3550, 1625, 1590. This product was used as such in the following step without purification.

Provenance & Evidence