Patent GB-864876-A (GB)
Title: Process of preparing bromomethyl methylol phenols
IPC: C08G8/28
Filed: 1958-09-18
Abstract: Brominated resols, having a bromine content of 1 to 9%, are made by reacting hydrogen bromide with a resol obtained by condensation of formaldehyde with a para-alkyl phenol wherein the alkyl group contains 4-20 carbon atoms.  The brominated resols may be of formula:- <FORM:0864876/IV (a)/1> wherein n=0, 1 or 2 and R is an alkyl group containing 4 to 20 carbon atoms, and wherein the hydrogen atom in the 2-position on the lefthand phenol unit may be substituted by an HOCH2- or BrCH2- group.  Specification 864,875 is referred to.ALSO:The invention comprises a process of preparing bromomethyl alkylphenol compositions by reacting a mono- or di-methylol-4-alkyl-phenol (wherein the alkyl group contains 4 to 20 carbon atoms), or a resitol obtained by splitting off water from said mono- or di-methylol-4-alkyl phenols, with hydrogen bromide or hydrobromic acid in an amount to form a product having a bromine-content of 1 to 9 per cent.  The compositions may include simple compounds such as mono- and di-bromomethyl-4-alkyl phenols, and low polymers such as <FORM:0864876/IV (b)/1> where n=O, 1 or 2, and compounds wherein the hydrogen in the 2- position of the left-hand phenol unit is substituted by an HOCH2- or BrCH2- respectively.  In Example 1, a solution of p-diisobutyl phenol in aqueous sodium hydroxide is reacted, at about 50 DEG C. for 12 hours, with formaldehyde.  The batch is neutralized with hydrochloric acid; and the water is removed by evaporation.  The mono- and di-methylol-p-diisobutyl phenol so obtained is heated at 125 DEG  to 130 DEG C., under reduced pressure, to give a tetramer (resitol) of melting-point 50 DEG C.  The resitol is dissolved in benzene; and the solution is treated, at 25 DEG  to 30 DEG  C. and with vigorous agitation, with hydrogen bromide gas.  The benzene is then removed by vacuum distillation (final temperature 95 DEG C), leaving a bromomethyl- and methylol-octyl-phenol polymer mixture containing 4,2% of combined bromine.  In Example 3, mono- and dimethylol-p-diisobutyl phenol is dehydrated under reduced pressure keeping the temperature below 50 DEG C. to minimize the formation of dimers.  The dehydrated batch is sparged with HBr gas; and the temperature is increased to 52 DEG C.  At this stage, the reaction mixture contains 2- bromomethyl-4-diisobutyl phenol and 2, 6-dibromomethyl-4-diisobutyl phenol.  The mixture is partially polymerized by heating it to 100 DEG C. under reduced pressure.  The resulting product contains 4,3% bromine.  Example 5 describes the action of gaseous HBr on dimethylol-p-diisobutyl phenol to give a mixture containing 2-bromomethyl-4-diisobutyl-6-methylol-phenol and 2,6-dibromomethyl-4-diisobutyl phenyl.  The mixture is then dehydrated by heating it to 80 DEG C. in vacuo.  The product contains 5,8% bromine.  Example 6 describes the bromination of dimethyl-p-diisobutyl phenol by means of 40% hydrobromic acid, and the subsequent dehydration of the reaction-mixture to give a product containing 6% bronime.  In Example 7, a tetramer containing 8% of bromine is prepared, starting from p-tert.-butyl phenol.  In Example 8, the starting-material is p-tert.-amyl phenol.  Another process for preparing the same type of compositions is the subject-matter of Specification 864,875.