Process for the preparation of nitrooxyderivatives of paracetamol

A process for preparing a compound of the following formula (I):

• wherein X is a straight or branched C1-C20-alkylene chain, said process comprising reacting a compound of the following formula (II):
• wherein M is a hydrogen atom or a cation of an alkaline or alkaline earth metal, an onium cation with a compound of the following formula (III):
• O2NO—X—COY (III)
• wherein Y is OH, Cl, OCOOR, —OCO—X—ONO2 wherein R is a C1-C6alkyl and X is as defined above.