METHOD FOR OBTAINING COMPOUNDS OF MORFINAN-6-ONE Russian patent published in 2018 - IPC C07D498/02 C07D489/08 

FIELD: chemistry.

SUBSTANCE: invention relates to process for preparation of compound of formula (3), comprising steps: (a) providing aqueous acidic solution containing a compound of formula (1) and, as an impurity, a compound of formula (2); and (b) treating the aqueous acid solution of step (a) in such a way that the compound of formula (2) is dehydrated to form the compound of formula (1) and the compound of formula (1) is reduced to form an aqueous acidic solution of the compound of formula (3), (1) (3) (2), in which: the treatment of step (b) is carried out at one or more temperatures higher than the value of the ambient temperature, in the presence of a heterogeneous hydrogenation catalyst based on a platinum group metal (PGM) and hydrogen gas; and in which for the compounds of formulas (1), (2) and (3): i) R₁ is -OH, R₂ is -OH and R₃ – -H; or ii) R₁ is -OCH₃, R₂ is -H and R₃ – -CH₃; or iii) R₁ is -OH, R₂ is -H and R₃ – -CH₃; or iv) R₁ is -OCH₃, R₂ is -H and R₃ – -H; or v) R₁ is -OH, R₂ is -H and R₃ – -H; or vi) R₁ is -OCH₃, R₂ is -OH and R₃ – -H. Invention also relates to another process variant for preparation of compound of formula (3).

EFFECT: improved methods for preparing a compound of formula (3) with a reduced amount of impurities and a high resistance to repeated increase of α, β-unsaturated ketones (ABUK) are provided.

25 cl, 2 dwg, 3 ex