- Synthesis method of 7-bromothieno [2, 3-B] pyrazine
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The invention provides a preparation method of 7-bromothieno [2, 3-b] [1, 2, 4] thiadiazole. The invention discloses a synthetic method of 2, 3-B] pyrazine. Relating to the organic synthesis field, the preparation method comprises the following steps: reacting 2, 3-dichloropyrazine with 2-methyl-3-butyne-2-ol, cuprous iodide and triethylamine under the catalytic action of tetrakis (triphenylphosphine) palladium to generate 2-methyl-4-(3-chloropyrazine)-3-butyne-2-ol; 2-methyl-4-(3-chloropyrazine)-3-butyne-2-ol reacts with alkali to obtain 2-chloro-3-ethynylpyrazine, 2-chloro-3-ethynylpyrazinereacts with sodium sulfide nonahydrate to generate thieno [2, 3-B] pyrazine, and thieno [2, 3-B] pyrazine further reacts with N-bromosuccinimide to generate 7-bromothieno [2, 3-. The synthesis methodprovided by the invention has the advantages of easily available raw materials, mild reaction conditions, high selectivity, good operability of post-treatment, high yield and easiness in large-scale production.
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Paragraph 0047; 0054-0056; 0060; 0065-0066; 0069; 0074-0075
(2020/09/12)
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