A new synthetic route of 5-Bromo-2,3-diphenylpyrazine

The synthetic route of 243472-70-0 has been constantly updated, and we look forward to future research findings.

243472-70-0, name is 5-Bromo-2,3-diphenylpyrazine, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Formula: C16H11BrN2

[00130] To 50 g (0.161 mol) of 5-bromo-2,3-diphenylpyrazine, 116 g (0.884 mol, 5.5 eq/mol) of 4-(isopropylamino)-butan-l-ol and 13.33 g of KI (0.080 mol, 0.5 Eq/mol) were added. The reaction mixture was stirred, warmed and then heated up to 140C for about 18- 20 hrs. The reaction was monitored by TLC up to completion (starting material about 1% by TLC). The reaction mixture was cooled down to room temperature. After the reaction was completed, the following work up step was performed: (0208) [00131] Option 1 : Ethyl acetate was added (500 mL, 10 vol) and the organic phase was washed with water (150 mL, 3 vol). The organic phase was separated and aqueous phase was extracted with ethyl acetate (150 mL, 3 vol). The organic phases were joined and washed with water (200 mL, 2 vol) three times. (0209) [00132] The solvent was distilled off under vacuum at not more than (“NMT”) 40C until 1 vol (oil appearance). (0210) [00133] Option 2: The material (mixture) was dissolved in acetone (250 mL, 5 vol), the solution obtained was cooled down to 0C to 5C and anti-solvent / water was added (1000 mL, 20 vol) for 40 minutes, then the suspension was stirred for about 30 minutes at about 0C-5C. The solid material was filtered and washed with water (200 mL, 4 vol). Crude wet product was obtained as yellow solid yielding 101.8 % WY (87 % MY), HPLC purity 90.8% on area at this stage. (0211) [00134] The crude material, obtained in either of the above described options, was purified through crystallization from acetone :-heptane as follows: to a solution of 4-((5,6-diphenyl- pyrazin-2-yl)(isopropyl)amino)butan-l-ol crude in acetone (175 mL, 3.5 vol) at 0C – 5C, hexane (600 mL, 12 vol) dropwise in about 120 min was added, then the precipitated mixture was cooled down to about -10C and stirred for about 60 min. The product was filtered off and washed with hexane (250 mL, 5 vol) and dried under vacuum at 25C. Pure product was obtained as yellowish solid yielding overall 77.2%, (66.5% MY), HPLC purity 98.2% on area.

The synthetic route of 243472-70-0 has been constantly updated, and we look forward to future research findings.