Preparation of phenols by direct N.sub.2 O hydroxylation of aromatic substrates

A process for the preparation of a phenol, comprising directly reacting an aromatic compound of the formula (I):

• ##STR2## in which R.sub.1 is an OH group, a bromine atom, a chlorine atom, a fluorine atom, a hydrogen atom, a straight or branched chain alkyl radical having from 1 to 6 carbon atoms, or a straight or branched chain alkoxy radical having from 1 to 6 carbon atoms, and R.sub.2 is a hydrogen atom, a straight or branched chain alkyl radical having from 1 to 6 carbon atoms, or a straight or branched chain alkoxy radical having 1 to 6 carbon atoms, at a temperature of 250.degree. C. to 500.degree. C., with nitrous oxide, in the presence of a modified zeolite which comprises:
• (a) a modified zeolite of ZSM-5 type of formula (II), expressed in terms of the oxide ratios thereof:
• M.sub.2 O, X.sub.2 O.sub.n, mSiO.sub.2, pH.sub.2 O (II)
• in which M is a cation selected from among hydrogen and the alkali metals, at least some of the cations M being a hydrogen atom;
• X is Ga, Fe, B, In, Cr, Sc, Co, Ni, Be, Zn, Cu, Sb, As or V;
• D is 2, 3 or 5, depending on the valency of the element X;
• m is a number greater than or equal to 20;
• and p is a number ranging from 0 to 40, or
• (b) a modified zeolite of ZSM-11 type of general formula (III), expressed in terms of the oxide ratios thereof:
• M.sub.2 O, Z.sub.2 O.sub.n, mSiO.sub.2, xH.sub.2 O (III)
• in which M is a cation selected from among hydrogen and the alkali metals, at least some of the cations M being a hydrogen atom;
• Z is Al, Ga, Fe, B, In, Cr, Sc, Co, Ni, Be, Zn, Cu, Sb, As or V;
• D is 2, 3 or 5, depending on the valency of the element Z;
• m is a number greater than or equal to 20;
• and x is a number ranging from 6 to 12.