Process for the production of phenolic compounds and intermediates for use therein

Claim 2

A process as claimed in claim 1 which is carried out in the presence of methanol as said alcohol.

Claim 3

A process as claimed in claim 3 in which tHe product is precipitated from solution in methanol by adding water.

Claim 4

A process as claimed in claim 4 in which 0.05 to 20 equivalents of hydrogen ions are present per mole of dienone.

Claim 5

A process as claimed in claim 1 in which the source of the hydrogen ions is sulphuric acid.

Claim 6

A process for preparing 4-methoxy-2,6-di-tert.-butyphenol, which comprises converting 2,4,6-tri-tert.butyl phenol to 4-methoxy-2,6 -di-tert.butyl phenol by adding to a solution of 2,4, 6 tri-tert. butyl phenol in methanol at a temperature in the range 50* to 120* C, at least an equimolar amount of sodium or potassium hypochlorite based on the 2,4,6 tri-tert.butyl phenol during a period of 5 minutes to 5 hours, diluting with water to produce an aqueous and a non-aqueous phase, separating the non-aqueous phase containing 4-methoxy-2,4,6-di-tert.butyl cyclohexa-di-2,5-ene-1-one, dissolving it in methanol, adding an acid selected from the group consisting of HCl, HBr, HI and H2SO4 so that the hydrogen ion equivalents per mole of dienone is in the range of 0.05 to 20, refluxing, and adding water to precipitate 4-methoxy-2,6 di-tert.butyl phenol.

Claim 7

A process for preparing 4-methoxy-2,6-di-tert-butyl phenol which comprises converting 2,4,6-tri-tert.butyl phenol to 4-methoxy-2,6-di-tert.butyl phenol by adding to a solution of 2,4, 6-tri-tert. butyl phenol in methanol at a tempterature in the range 50* to 120*C. at least an equimolar amount of sodium or potassium hypochlorite based on the 2,4,6-tri-tert.butyl phenol during a period of 5 minutes to 5 hours, diluting with water to produce an aqueous and a non-aqueous phase, separating the non-aqueous phase, heating it in the presence of a C1-3 alcohol solvent and an acid selected from the group consisting of HCl, HBr, HI and H2SO4 so that the hydrogen ions are in the range of 0.5 to 20 equivalents per mole of dienone, to a temperature of from 50* C to 200* C, and separating 4-methoxy-2,6-di-tert.butyl phenol.

Claim 8

A process for preparing 4-methoxy-2,6-di-tert. butyl phenol which comprises converting 2,4,6-tri-tert. butyl phenol to 4-methoxy-2,4,6-tri-tert. butyl cyclohexa-di-2,5-ene-1 one by reacting said phenol with an alkali metal hypochlorite or hypobromite in the presence of a polar solvent selected from the group consisting of alcohols having 1 to 3 carbon atoms, water, ethylene glycol, acetonitrile, formic acid, acetic acid, dimethyl formamide and dimethyl sulphoxide, and then converting the resulting 4-methoxy-2,4,6-tri-tert. butyl cyclohexa-di-2,5-ene-1-one to 4-methoxy 2,6-di-tert. butyl phenol by heating in an alcohol having one to three carbon atoms in the liquid phase with hydrogen ions supplied by an inorganic acid selected from the group consisting of HCl, HBr, HI and H2SO4.

Claim 9

A process as claimed in claim 9 wherein the 2,4,6-tri-tert.butyl phenol is converted to said dienone by reacting the same with methanol and an alkali metal hypochlorite or hypobromite in a proportion of 1.5 to 3 moles of hypochlorite or hypobromite per mole of said phenol.

Claim 10

A process as claimed in claim 10 in which a molar excess of 200 to 500 percent of the alcohol is present.

Claim 11

A process as claimed in claim 11 when carried out under reflux.

Claim 12

A process as claimed in claim 12 in which an alkali metal hypochlorite is added to 2,4,6-tri-tert.butyl phenol in the presence of methanol at a temperature of at least 50*C under reflux over a period of 5 minutes to 5 hours, maintaining the temperature in excess of 50*C after the commencement of the addition of hypochlorite for a period in the range 1 to 5 hours.

Claim 13

A process as claimed in claim 13 in which the temperature is maintained in excess of 50*C for a period of at least 15 minutes after the completion of the addition of the alkali metal hypochlorite.