METHOD OF PRODUCING ISOCYANATES Russian patent published in 2011 - IPC C07C263/04 C07C265/14 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing isocyanates without using toxic phosgene. The method involves subjecting alkyl carbamate of formula , where R³ is a straight alkyl group containing 1-20 carbon atoms; bis(C₅-C₆cycloalkyl)alkyl group containing 11-20 carbon atoms; C₅-C₆-cycloalkyl alkyl group containing 6-20 carbon atoms, where the cycloalkyl ring can be substituted with 1-3 substitutes selected from alkyl containing 1-8 carbon atoms; and an aromatic group containing 6-20 carbon atoms and having 1 or 2 benzene rings; R³ has valence equal to n, R⁴ is an alkyl group containing 1-20 carbon atoms, n equals 2, to thermal decomposition in the presence of an aromatic hydroxy compound, having a substitute in at least one ortho-position relative the hydroxyl group, of formula , where ring A is a benzene ring which can contain an additional substitute R² in another ortho-position relative the hydroxy group; R¹ is a group different from a hydrogen atom, which is an alkyl group containing 1-20 carbon atoms; an alkoxy group containing 1-20 carbon atoms; or a phenylalkyl group containing 7-20 carbon atoms; an additional substitute R² is selected from hydrogen or alkyl group containing 1-20 carbon atoms.

EFFECT: method increases output of isocyanates and lowers the amount of by-products accumulating inside the reactor.

11 cl, 4 dwg, 35 ex