Hydrochloric Acid → Phenol, 2-[(1E)-2-(2-bromophenyl)ethenyl]-4-chloro-, 1-acetate

Participants

Reaction Steps

2-Bromobenzyl bromide (25 g, 0.100 mol) and toluene (25 ml) were heated to 100° C. Next triethyl phosphite (19.3 ml, 0.108 mol) was added over 30 minutes, while the temperature was kept below 116° C. The mixture was stirred for 4 hours at 115° C., while the toluene was distilled. The mixture was cooled to room temperature and diluted with tetrahydrofuran (THF; 16.5 ml). KOtBu (30.5 grams, 0.250 mol) was dissolved in THF (176 ml) and cooled to −10° C. The (2-bromobenzyl)-phosphonic acid diethyl ester solution was added at −5° C. Next chlorosalicylaldehyde (17.2 g, 0.110 mol) in THF (62 ml) was added at −10° C. The mixture was stirred for one hour at −5° C. to 0° C. When the reaction was complete acetic anhydride (24.5 ml, 0.36 mol) was added and the temperature was allowed to rise to 20° C. The reaction was stirred for another 15 min and then cooled to 5° C. The pH of the reaction mixture was adjusted to 5 by the addition of 200 ml 1N HCl. The organic layer was separated and washed with 200 ml saturated NaCl solution. The organic layer was evaporated under reduced pressure at 50° C., yielding (E)-2-(2-bromostyryl)-4-chlorophenyl acetate in 25.8 grams, (73%).

Provenance & Evidence