ANTI-VIRAL COMPOUND PRODUCTION Russian patent published in 2017 - IPC C07D403/04 C07D403/14 

FIELD: pharmacology.

SUBSTANCE: invention relates to a process for preparation of a compound of formula I or a pharmaceutically acceptable salt thereof comprising (A) reaction of a combination of formula compound (i) with formula compound (ii) in the presence of a metal catalyst and a base to obtain a compound of formula (iii) or a salt thereof; (B) deprotection of a compound of formula (iii) to obtain a compound of formula (iv) or a salt thereof; (C) bringing the compound of formula (iv) into contact with (S)-2-(methoxycarbonylamino)-3-methylbutanoic acid to obtain a compound of formula I; each PG being independently t-butoxycarbonyl, benzyloxycarbonyl or methoxy or isopropyloxycarbonyl protecting group; Y and Z are independently selected from Br and -B (OR)(OR'), where Y is -B (OR)(OR'), then Z is Br and Y is Br, then Z is - B(OR)(OR'); and R and R' are independently selected from the group consisting of hydrogen and straight or branched C_1-8-alkyl, or R and R' together represent C_3-8-cycloalkylene, wherein any alkyl or cycloalkylene is optionally substituted by one or more C_1-6-alkyl groups. The invention also relates to intermediates and their crystalline forms.

EFFECT: useful for hepatitis treatment.

26 cl, 2 dwg, 2 ex