Reaktion #1604366

Reaktionsgleichung

Water

O-ethyl hydrazinecarbothioate

2-bromo-1-[1-isobutyl-2-(3-methoxyphenyl)-1H-benzimidazol-5-yl]ethanone hydrochloride

pyridine

→

5-[1-isobutyl-2-(3-methoxyphenyl)-1H-benzimidazol-5-yl]-3,6-dihydro-2H-1,3,4-thiadiazin-2-one

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe resulting mixture is extracted with ethyl acetate
2. 2
   WaschenThe organic phase is washed with water
3. 3
   Trocknendried over anhydrous sodium sulfate
4. 4
   Sonstigeevaporated under vacuum
5. 5
   SonstigeThe residue is purified on a column of silica
6. 6
   SonstigeThe residue obtained
7. 7
   Sonstigeafter evaporation
8. 8
   Sonstigeto give
9. 9
   Filtrationafter filtration, 10 g of 5-[1-isobutyl-2-(3-methoxyphenyl)-1H-benzimidazol-5-yl]-3,6-dihydro-2H-1,3,4-thiadiazin-2-one in the form of a light-beige solid

Vorschrift

To a solution of 24 g (54.8 mM) of 2-bromo-1-[1-isobutyl-2-(3-methoxyphenyl)-1H-benzimidazol-5-yl]ethanone hydrochloride in 500 ml of ethanol are added 6.3 ml (78.4 mM) of pyridine and then 8.2 g (78.4 mM) of O-ethyl hydrazinecarbothioate. The reaction medium is then maintained at 80° C. with stirring for 20 hours. Water is then added and the resulting mixture is extracted with ethyl acetate. The organic phase is washed with water and then dried over anhydrous sodium sulfate and evaporated under vacuum. The residue is purified on a column of silica, using a dichloromethane/methanol mixture (98/2). The residue obtained after evaporation is taken up in diethyl ether to give, after filtration, 10 g of 5-[1-isobutyl-2-(3-methoxyphenyl)-1H-benzimidazol-5-yl]-3,6-dihydro-2H-1,3,4-thiadiazin-2-one in the form of a light-beige solid.

Quelle