2-(p-t-butylphenyl)ethynyl)-3-(p-t-butylphenyl)-1,4-dimethylnaphthalene and the method of its preparation

Abstract

The subject of the application is 2-(p-tert-butylphenylethynyl)-3-(p-tert-butylphenyl)-1,4-dimethylnaphthalene and a method for its preparation consisting in introducing ethyl 2-methylacetoacetate into a reactor and adding per 1 mmol of this compound: from 1 to 5 mmol of 1,4-bis(p-tert-butylphenyl)-1,3-butadiyne, from 25 to 250 molecular sieves, from 0.01 to 0.1 mmol of catalyst, i.e. bromo-tri(carbonyl)-(tetrahydrofuran)rhenium(I) dimer, and from 1 to 20 low-boiling alkylbenzene, after which the resulting reaction mixture is stirred and simultaneously heated at a temperature of 120°C to 220°C for a time of 1 to 20 minutes. 120 hours, then the reaction mixture is cooled to ambient temperature, then from 1 to 5 mmol, from 1 to 20 ml of acetonitrile and from 0.5 to 2 mmol of the benzine precursor, i.e. 2-(1-trimethylsilyl)phenyl trifluoromethanesulfonate, are added, and the whole is stirred at a temperature of from 10°C to 50°C, for a time of from 1 to 120 hours,then, in the next step, volatile fractions are evaporated from the post-reaction mixture using a vacuum rotary evaporator, and the crude product is isolated from the solid residue by column chromatography on silica gel using a low-boiling system, saturated hydrocarbon - low-boiling, chlorinated hydrocarbon, mixed in a volume ratio of 20:1 to 1:25 as the eluent, and then, preferably, the crude product is purified by carrying out another column chromatography process on silica gel using a low-boiling system, saturated hydrocarbon - low-boiling, aromatic hydrocarbon, mixed in a volume ratio of 20:1 to 1:25 as the eluent, to finally obtain 2-(p-tert-butylphenylethynyl)-3-(p-tert-butylphenyl)-1,4-dimethylnaphthalene with a yield of up to 80% and with a purity of not less than 98%.,