2-Bromophenol → 8-Bromo-2H-1-benzopyran-3(4H)-one

Participants

Reaction Steps

8-Bromochroman-3-one 28B was prepared from 2-bromophenol in a manner similar to that described in the literature (J. Med. Chem., 1988, 689): Reaction of 2-bromophenol with paraformadehyde (MgCl2, NEt3, THF, 75° C., 4 h), followed by treatment with acrylonitrile (neat, Dabco, 95° C., 18 h), and hydrolysis with 10% NaOH (100° C., 4 h) afforded 28A. Compound 28A was reacted with DPPA (NEt3, toluene, 110° C., 2 h) followed by treatment with 6N HCl (85° C., 2 h) to afford 8-bromochroman-3-one 28B.

Provenance & Evidence