METHOD OF PRODUCING ENAMINES Russian patent published in 2016 - IPC C07D295/84 C07C209/52 C07C323/27 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing enamines, which are useful for various reactions, which include electrophilic substitution and connection, oxidation and reduction. Method includes: (A) reaction of amine and carbonyl compound in reaction zone, which contains a solvent to form enamine and H₂O according to following procedure:

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Reaction in said reaction zone is carried out in conditions of azeotropic distillation at (a) pressure of 100 Pa to 120,000 Pa and (b) temperature lower than thermal decomposition of said enamine during said interaction; c) said solvent at initial stage comprises a nonpolar liquid with high boiling point, mainly, benzene, toluene or xylene, polar liquid with high boiling point, mainly, acetonitrile or ethanol, and further additionally contains H₂O, obtained from condensation of said amine and said carbonyl compound at formation of said enamine, B) removal of vapour phase containing H₂O, from said reaction zone. Mainly pressure during distillation is 5,000-15,000 MPa and temperature from 25 to 65 °C, ratio of amine to carbonyl compound preferably more than 1, but less than 1.1. In amine of formula (III) each of R4 and R5 is independently selected from C₁-C₈alkyl, C₃-C₈cycloalkyl, C₂-C₈alkoxyalkyl, C₇-C₁₂arylalkyl, C₂-C₈alkylaminoalkyl, aryl and heteroaryl, or R4 and R5, taken together with N represent 5- or 6-member saturated or unsaturated ring; and said carbonyl compound is aldehyde or ketone of formula (II) or said carbonyl compound is a 3-methylsulphanyl-butyraldehyde. In carbonyl compound of formula (II) each of R1 and R2 is independently selected from C₁-C₈alkyl, C₃-C₈cycloalkyl, C₂-C₈alkoxyalkyl, C₇-C₁₂arylalkyl, C₂-C₈alkylaminoalkyl, aryl and heteroaryl, each independently substituted with one or more groups of S-R6, where each R6 is independently selected from C₁-C₈alkyl, C₃-C₈cykloalkyl, C₂-C₈alkoxyalkyl, C₇-C₁₂arylalkyl, C₂-C₈alkylaminoalkyl, aryl and heteroaryl, and R3 is selected from H, C₁-C₈alkyl, C₃-C₈cykloalkyl, C₂-C₈alkoxyalkyl, C₇-C₁₂arylalkyl, C₂-C₈alkylaminoalkyl, aryl and heteroaryl.

EFFECT: method enables to manufacture products with higher output and simplifies process by avoiding need to use solid desiccants which require additional separation stage, or reducing their amount.

22 cl, 2 ex