METHOD FOR TRIMETHYL SUBSTITUTED FURODIHYDROQUINOLINES SYNTHESIS Russian patent published in 2017 - IPC C07D491/48 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for 7,7,9-trimethyl-6,7-dihydro-furo[3,2-ƒ]quinoline synthesis, comprising the 5-aminobenzofuran condensation with acetone in the presence of n-toluenesulphonic acid and magnesium perchlorate at a temperature of 70-125°C in an autoclave. At that, 5-aminobenzofuran is obtained by a sequence of steps consisting of: a - n-anisidine acylation with acetic anhydride to give N-(4-methoxyphenyl)acetamide; b - N-(4-methoxyphenyl)acetamide obtained in step interaction with chloroacetyl chloride to give N-[3-(chloroacetyl)-4-hydroxyphenyl]acetamide; c - dihydrofurane cycle circuit closure by treating the product obtained in step b by sodium acetate and subsequent intermediate reduction without isolation from the reaction mixture by sodium borohydride to yield N-(3-hydroxy-2,3-dihydro-1-benzofuran-5-yl)acetamide; d - dehydration of the product obtained in step c by treatment with n-toluenesulphonic acid and magnesium perchlorate to yield N-1-benzofuran-5-yl acetamide; e - acidic hydrolysis of the product obtained in step d to yield 5-aminobenzofurane. The method may be used as the basis for synthesis of various derivatives of furodihydroquinolines (FDHQ) trimethyl substituted by quinoline ring, that are of practical interest as potential sensitizers for application in PUVA-treatment of skin diseases, and they may be used in various fields of technology as antioxidants and antiozonants .

EFFECT: simplification and cheapening of the desired product obtaining process and increase of its total output compared with the prototype.

2 dwg, 2 ex