Patent GB-744425-A (GB)
Title: Production of phenols and esters thereof
Inventor: JACOBS DAVID IAN HUTCHINSON
Filed: 1953-09-05
Abstract: Carbinol aryl hydroperoxides of the formula <FORM:0744425/IV(a)/1> where R1 is hydrogen, alkyl or alicyclic, R2, R3 and R4 are alkyl or alicyclic and Ar is an aromatic hydrocarbon nucleus to which the substituent groups above are attached at nonadjacent carbon atoms, are decomposed with an acidic catalyst under anhydrous conditions to produce phenol alcohols of the formula <FORM:0744425/IV(a)/2> and aldehydes or ketones of the formula <FORM:0744425/IV(a)/3> where R1, R2, R3, R4, and Ar are as indicated above.  The phenol-alcohols may be heated in the presence of an acid anhydride to produce an ester of the corresponding alkenyl phenol of the formula <FORM:0744425/IV(a)/4> where R4 and Ar are as indicated above and R5 is the unsaturated radical corresponding to and formed by the dehydration of R3.  The free alkenyl phenol may be formed by hydrolysis of the ester or directly by thermal dehydration of the phenol alcohol.  The alkenyl phenyl ester may be produced in a single stage by decomposing the carbinol aryl hydroperoxide with the decomposition catalyst in the presence of the acid anhydride between 40-100 DEG  C.  The radicals R1, R2, R3 and R4 may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec.-butyl, cyclopentyl, or cyclohexyl, and the nucleus Ar may be benzene, naphthalene, anthracene or phenanthrene or their alkyl-substituted derivatives. Groups R3 and R4 may be linked to form a single bivalent cycloalkyl group such as cyclopentyl.  Specific examples of hydroperoxides which may be decomposed are m - (2 - hydroxy - 2 - propyl) - a ,a  - dimethylbenzyl hydroperoxide to give m-(2-hydroxy - 2 - propyl) - phenol and acetone; m - (2 - hydroxy - 2 - butyl) - a  - methyl - a - ethyl benzyl hydroperoxide to give m-(2-hydroxy - 2 - butyl) - phenol and methyl - ethylketone; p - (1 - hydroxycyclopentyl) - a ,a - dimethylbenzyl hydroperoxide to give p-(1-hydroxycyclopentyl)-phenol and acetone; 1-(11-hydroxycyclopentyl) - 3 - (21 - propyl - 21 - hydroperoxy) - naphthalene to give 1 - (11 - hydroxycyclopentyl) - 3 - hydroxy - naphthalene and acetone; and p-(2-hydroxy-2-propyl)-a -methylbenzyl hydroperoxide to give p-(2-hydroxy-2-propyl)-phenol and acetaldehyde. The carbinol aryl hydroperoxide used may be the crude oxidation product from the oxidation of the monocarbinol. <FORM:0744425/IV(a)/5> where R1, R2, R3, R4 and Ar are as indicated above or of a mixture containing such a carbinol.  The hydroperoxide is preferably concentrated by fractional distillation or extraction before being decomposed.  The decomposition is conducted in an organic solvent such as acetone, methyl ethyl ketone, benzene, toluene xylene, chlorobenzene, chloronaphthalene, diisopropyl ether, methyl isobutyl ketone, cyclohexanone, 2-hexanone or mixtures of these solvents. Decomposition catalysts which may be used are those known to catalyse the decomposition of an a ,a -dialkyl aryl methyl hydroperoxide and are acidic condensation catalysts such as hydrochloric acid, sulphuric acid, sulphur dioxide, montmorillonites, bentonites, kaolinites, illite, attapulgite, fuller's earths, benzene sulphonic acid, p-toluene sulphonic acid, sulphonated phenol formaldehyde, sulphonated styrene divinyl benzene polymers, phosphorus pentachloride, phosphorus oxychloride, mono-, di-, and tri-chloracetic acids and vermiculite.  The temperature of the decomposition may be between 0 DEG  and 100 DEG  C.  The presence of water may retard or stop the reaction.  The process may be worked batchwise or continuously. The product is isolated after removal of the catalyst and solvent either by recrystallizing from a solvent such as benzene, or azeotropically distilling under reduced pressure with an inert high-boiling liquid such as methyl naphthalene, gas oil, tri-isopropyl benzene, chloronaphthalene, bromonaphthalene or mixtures of these liquids, the product crystallizing from the distillate on cooling.  The dehydration to the alkenyl phenol may be conducted either by refluxing the phenol alcohol in an acid anhydride such as acetic anhydride or propionic anhydride to form the alkenyl phenyl ester which may then be hydrolysed or by distillation of the phenol alcohol without an entrainer at or below atmospheric pressure, or by catalytically decomposing the hydroperoxide in the presence of the acid anhydride when the solvent may be acetic anhydride, the decomposition catalyst may be sulphuric acid or fuller's earth and the reaction mixture may be heated at less than 100 DEG  C.  The product is isolated by fractionation after removal of the catalyst and solvent.  In examples:  (1) m-(2-hydroxy-2-propyl)-a ,a -dimethylbenzyl hydroperoxide in dry benzene is added to a refluxing solution of sulphuric acid in dry acetone, neutralized with magnesium oxide, the solution filtered, the solvent removed and the residue crystallized to give m-(2-hydroxy-2-propyl)-phenol; (2) illustrates a similar reaction using fuller's earth as catalyst; (3) m - (2 - hydroxy - 2 - propyl) - a ,a  - dimethylbenzyl hydroperoxide in acetic anhydride is added to sulphuric acid in acetic anhydride, neutralized with sodium acetate, the solvent and sodium sulphate removed and the residue fractionated to give m-isopropenyl phenyl acetate; (4) illustrates the previous reaction using fuller's earth as catalyst; (5) illustrates the decomposition of m-(2-hydroxy-2-butyl) - a  - methyl - a  - ethylbenzyl hydroperoxide using p-toluene sulphonic acid, benzene sulphonic acid and trichloracetic acid as catalysts. Specification 743,210 is referred to.