Реакция #6539

Уравнение реакции

sulfuric acid

6-demethyl-6-deoxytetracycline

N-bromosuccinimide

diethyl ether

→

pure product

7-Bromo-4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide sulfate

Условия реакции

Обработка

1. 1
   ДругоеThe resulting precipitate is collected
2. 2
   Другоеdried
3. 3
   workup.DISSOLUTIONThe solid is dissolved in 2-methoxyethanol
4. 4
   Другоеtriturated with methanol
5. 5
   Другоеcollected
6. 6
   Промывкаwashed with methanol and diethyl ether
7. 7
   Другоеdried
8. 8
   Другоеto give 6.22 g of crude product
9. 9
   ДругоеThe solid is recrystallized from 2-methoxyethanol and methanol

Методика

A solution of 4.14. g of 6-demethyl-6-deoxytetracycline, prepared by the described literature procedure, and 1.99 g of N-bromosuccinimide dissolved in 50 ml of concentrated sulfuric acid is stirred at 0° C. for 45 minutes or until solution occurs. The reaction mixture is added dropwise to 2 L of cold diethyl ether. The resulting precipitate is collected and dried. The solid is dissolved in 2-methoxyethanol, triturated with methanol, collected, washed with methanol and diethyl ether and dried to give 6.22 g of crude product. The solid is recrystallized from 2-methoxyethanol and methanol to give 3.1 g of pure product. MS(FAB): m/z 493 (M+H). 1H NMR(CD3SOCD3): δ 4.3(s, lH, 4-H), 6.8(d, lH, 9-H) and 7.75(d, IH, 8-H).

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