Hydrogen Bromide → HCID 178419253, compound

Participants

Reaction Conditions

Reaction Steps

A 25° C. suspension of 75 g (0:17 mol) of 5-amino-N,N-diethyl-8-methoxy-2H-[1]benzothiopyrano[4,3,2-cd]indazole-2-ethanamine, dihydrochloride (1) in 1.35 L of dichloroethane was treated dropwise with 213 g (0.85 mol) of boron tribromide. The mixture was heated at 78° C. for 16 hr, treated cautiously with 1.5 L of methanol, then heated at reflux for 6 hr. After cooling to 25° C., then chilling at -5° C. overnight, the precipitated solids were collected by filtration, washed with cold methanol, and dried at 2 mm/48° C./24 hr to give 84.3 g (96%) of 7 as a salt with 2.0 equivalents of hydrogen bromide, mp 318° C. (dec), 98.3% pure by HPLC.

Provenance & Evidence