Patent ID: 7005553

Claim:
A method for the preparation of compounds of formula I wherein: the terms R′ and R″ may be the same or different and represent: hydrogen; lower alkyl; hydroxy; lower alkoxy; halogen; the group —CO—R 1 , wherein R 1 signifies hydrogen, hydroxy, alkylaryl, alkylheterocycloalkyl or optionally substituted saturated or partially unsaturated lower alkyl or aryl group, or R 1 signifies the group —O—R 2 , wherein R 2 signifies a lower alkyl or aryl group; the group —C═N—R a , wherein R a signifies NHR a , wherein R a represents optionally substituted lower alkyl or aryl group, or OR b group, where R b signifies hydrogen, lower alkyl or lower alkanoyl; the group —C—R c R d , where R c signifies an optionally substituted alkylidene, where R d represents OR e group where R e signifies optionally substituted lower alkanoyl or aryl group; or R′ and R″ taken together signify an optionally substituted saturated or partially unsaturated carbocyclic ring; m and n are independently 0, 1 or 2; the term lower alkyl means a carbon chain, straight or branched, containing from one to six carbon atoms; the term halogen means fluorine, chlorine, bromine or iodine; the term heterocycloalkyl means a five or six-membered cyclic ring incorporating one or two atoms of oxygen, sulphur or nitrogen; the term aryl means a phenyl or naphthyl group optionally substituted by alkoxy, halo or nitro groups; said method comprising reacting a phenolic compound of formula II: wherein the terms R′ and R″, m and n are defined above, with an alkyl nitrate of formula III R 3 —ONO 2 FORMULA III where R 3 represents an alkyl group straight or branched, containing from one to sixteen carbon atoms, or R 3 represents a cycloalkyl group containing either five or six carbon atoms, said reaction of the phenolic compound of formula II with the alkyl nitrate of formula III being carried out in the presence of an acid catalyst.