Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 243472-70-0, name is 5-Bromo-2,3-diphenylpyrazine, A new synthetic method of this compound is introduced below., Recommanded Product: 5-Bromo-2,3-diphenylpyrazine
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-1-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: 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. The solvent was distilled off under vacuum at not more than (“NMT”) 40C until 1 vol (oil appearance). Option 2: The material (reaction mixture obtained in step a) was dissolved in acetone (250 mL, 5vol), 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 % Weight Yield (WY) (87 % Molar Yield (MY)), HPLC purity 90.8% on area at this stage. 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-1-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 basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; TEVA PHARMACEUTICALS INTERNATIONAL GMBH; TEVA PHARMACEUTICALS USA, INC.; VILLALVA, Nidia; CANTE, Ivon; AYBAR, Martin; RODRIGUEZ, Angel; TORRES, Alejandro, Guillen; KANTOR, Hana; GAVENDA, Ales; HERRERA, Hugo; JEGOROV, Alexander; LOPEZ, Nydia; (40 pag.)WO2017/40872; (2017); A1;,
Pyrazine – Wikipedia,
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