FIELD: chemistry.
SUBSTANCE: present invention relates to use of an ortho-nitrosophenol compound in inhibiting polymerisation of ethylenically unsaturated monomers. Described is a method of inhibiting premature polymerisation ethylenically unsaturated monomers during distillation or purification, carried out in the absence of oxygen, involving adding to the said monomers an effective amount of at least one nitroso inhibitor, having the structure: 
in which R1 R2, R3 and R4 are independently selected from a group comprising hydrogen, and where adjacent groups R1, R2, R3 and R4 taken together, form a unsubstituted condensed six-member ring. Described also is a chemical composition containing: a) an ethylenically unsaturated monomer and b) an effective inhibiting amount which is sufficient for preventing premature polymerisation during distillation or purification of the said ethylenically unsaturated monomer in the absence of oxygen of at least one nitroso compound, having the structure given above.
EFFECT: preventing premature polymerisation of ethylenically unsaturated monomers.
13 cl, 1 tbl, 1 ex
