Реакция #344321

Уравнение реакции

carboxybenzo-1,2,3-thiadiazole

triethyl borate

methanol

→

title compound

7-hydroxymethylbenzo-1,2,3-thiadiazole

Растворители

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   workup.ADDITIONthere are added dropwise under a nitrogen atmosphere
2. 2
   workup.STIRRINGThe mixture is stirred overnight
3. 3
   Другоеto stand at room temperature
4. 4
   Температураcooled down to 5°-10° C.
5. 5
   workup.STIRRINGwith stirring
6. 6
   ДругоеThe mixture is subsequently evaporated in vacuo
7. 7
   workup.ADDITIONa further 300 ml of methanol are added
8. 8
   Другоеthe mixture is re-evaporated
9. 9
   ДругоеThe residue is purified on silica gel (solvent: ethyl acetate/hexane)
10. 10
    Другоеthe product obtained
11. 11
    Другоеis recrystallised from ethyl acetate/hexane

Методика

To a suspension of 54 g of carboxybenzo-1,2,3-thiadiazole in 420 ml of tetrahydrofuran there are added dropwise under a nitrogen atmosphere with stirring at room temperature 110 ml of triethyl borate, the mixture is stirred for a further hour and subsequently treated dropwise with 45.6 ml of boranedimethyl sulfide complex in 60 ml of tetrahydrofuran, with gentle cooling, during which process gas is evolved vigorously. The mixture is stirred overnight and allowed to stand at room temperature and then cooled down to 5°-10° C. and treated dropwise with 200 ml of methanol with stirring and vigorous cooling, during which process gas is again evolved vigorously. The mixture is subsequently evaporated in vacuo, a further 300 ml of methanol are added, and the mixture is re-evaporated. The residue is purified on silica gel (solvent: ethyl acetate/hexane), and the product obtained is recrystallised from ethyl acetate/hexane. The title compound obtained melts at 79°-81° C.

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