Methanol → HCID 178419254, compound

Participants

Reaction Steps

A 25° C. solution of 324.1 g (0.598 mol) of 2-[2-[[2-[2-(diethylamino)ethyl]-8-methoxy-2H-[1]benzothiopyrano[4,3,2-cd]indazol-5-yl]amino]ethyl]-1H-isoindole-1,3(2H)-dione (2) in 7.45 L of dichloromethane was treated dropwise over 2 hr with 2.1 L (2.1 mol) of a 1M solution of boron tribromide in dichloromethane. The mixture was heated at reflux for 6.75 hr, treated with an additional 300 mL (0.3 mol) of boron tribromide solution, then further heated overnight. The refluxing mixture was treated cautiously with 1.86 L of methanol, heated an additional 12 hr, then cooled and stirred for 3 hr in an ice bath. The solids were collected by filtration, washed successively with dichloromethane and hexane, then dried at 220 mm/45° C./20 hr to give 291.8 g (70.8%) of 3, mp 232.5°- 234° C., 98.9% pure by HPLC.

Provenance & Evidence