High purity alkylidene-bis:di:bromo-phenol prepn. - by reacting bromine and alkylidene-phenol in methanol and adding water

摘要

Prepn. of an alkylidenebis(dibromophenol) (I), (pref. 4,4'-isopropylidenebis (2,6-dibromophenol) (Ia) involves, dissolving alkylidenediphenol (II) in 17-25 mole MeOH per mole (II), (MeOH water content under 5, pref. 2 wt.%); adding 4.0-4.1 mole Br2 per mole (II) at an elevated temp. over less than 0.5 (pref. 0.25) hr; adding H2O to ppte. the (I) remaining in soln. after Br2 addn.; and sepg., from the MeOH soln., (I) which has an 13HA colour number of 20 max. High purity prods. of lower colour are produced with less energy than with previous processes, e.g. US3182088. (I) are useful in reactions with epichlorohydrin in epoxy resins mfr. (esp. those resistant to burning) and as precursors in clear plastics mfr. /0.