Patent ID: 6696591
Filing Date: 2004-02-24
Classification: C07C

Abstract:
A process for obtaining compounds of formula (I): wherein:R1 is the OCOR3 group; wherein R3 is methyl, ethyl or linear or branched C3-C5 alkyl or saturated heterocyclic ring having 5 atoms, containing heteroatoms independently selected between O and N; R2 is hydrogen, halogen, linear or branched when possible C1-C4 alkyl, linear or branched when possible C1-C4 alkoxyl; linear or branched when possible C1-C4 perfluoroalkyl; mono- or di-(C1-C4)alkylamino; said process comprising the following steps: a) reaction between an halide and a salicylic acid derivative formula (I-A) â€ƒwherein Hal&boxH;Cl, Br, and R1 and R2 have the above indicated meaning, with hydroxybenzylalcohol in the presence of a base in an organic solvent, or in a mixture of water with an organic solvent miscible or immiscible in water, to give the compound (I-B) having the following formula: â€ƒwherein R1 and R2 are as above defined; b) nitration of the compound (I-B) in anhydrous conditions, in an inert organic solvent, by a mixture formed by steaming nitric acid with an inorganic acid different from nitric acid, or with an organic acid, or with an anhydride of one or two organic acids to give the nitroxy derivative formula (I). c) recovery of the final product by adding water to the organic phase, separating the phases, drying and evaporating the organic phase.