METHOD OF PRODUCING PARA-TERPHENYL OF SCINTILLATION QUALITY Russian patent published in 2022 - IPC C07C15/14 C07C17/12 C07F3/02 C07F5/00 C07C1/32 C07C7/14 

FIELD: chemistry; technological processes.

SUBSTANCE: invention relates to a method for selective production of p-terphenyl from benzene, involving the following steps: i) reacting benzene and bromine to obtain a mixture of bromobenzene and 1,4-dibromobenzene under conditions which enable to selectively isolate 1,4-dibromobenzene without 1,2-dibromobenzene impurities; ii) adding to the obtained at step i) bromobenzene of magnesium in a polar aprotic solvent, suitable for producing a Grignard reagent; iii) adding excess trimethyl borate to the obtained at step ii) Grignard reagent at a temperature below -60 °C, followed by obtaining phenylboronic acid Ph-B(OH)₂; iv) addition of 1,4-dibromobenzene obtained at step i) to the phenylboronic acid obtained at step iii), in ratio 4:1 and catalytic amounts of palladium acetate (Pd(OAc)₂), followed by heating of the obtained mixture to temperature of 40–60 °C; v) removing the aprotic solvent from the reaction mixture obtained in step iv), and separating p-terphenyl from the mixture by recrystallisation with a product output of more than 94 %; wherein step i) is carried out while heating to 20–60 °C for 1–2 hours without an additional solvent in the presence of a catalyst selected from Fe, Mg₃Hg or pyridine (Py); where the aprotic solvent is diethyl ether, and step iv) is carried out while stirring for 8 hours.

EFFECT: use of the proposed method enables to accelerate the process, reduce power consumption during its implementation and obtain a product of high purity.

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