Реакция #63756

Уравнение реакции

sodium hydroxide

5-(trifluoromethyl)-2-benzimidazolethiol

2-chloromethyl-4-methoxy-3,5-dimethylpyridine hydrochloride

→

2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]-5-(trifluoromethyl)benzimidazole

Растворители

—

alcohol

water

Условия реакции

Обработка

1. 1
   Температураwhile cooling with ice
2. 2
   workup.WAITthe mixture is left
3. 3
   Температураat reflux overnight
4. 4
   Другоеsubsequently evaporated to dryness in vacuo
5. 5
   workup.DISSOLUTIONThe residue is dissolved in 1.5 l of methylene chloride
6. 6
   ПромывкаThe solution is washed firstly with 200 ml of 1.5N sodium hydroxide solution
7. 7
   Сушка3 x with 700 ml of water, dried over sodium sulphate
8. 8
   Другоеevaporated in vacuo
9. 9
   ДругоеThe crude product is purified on 360 g of silica gel with ethyl acetate/methylene chloride (1:1) as the elution agent
10. 10
    ДругоеCrystallization from methylene chloride/petroleum ether

Методика

21.8 g of 5-(trifluoromethyl)-2-benzimidazolethiol are suspended in 400 ml of alcohol and treated with 22.2 g of 2-chloromethyl-4-methoxy-3,5-dimethylpyridine hydrochloride while cooling with ice. Thereafter, a solution of 8.0 g of sodium hydroxide in 300 ml of water is added dropwise thereto, the mixture is left to boil at reflux overnight and subsequently evaporated to dryness in vacuo. The residue is dissolved in 1.5 l of methylene chloride. The solution is washed firstly with 200 ml of 1.5N sodium hydroxide solution and then 3 x with 700 ml of water, dried over sodium sulphate and evaporated in vacuo. The crude product is purified on 360 g of silica gel with ethyl acetate/methylene chloride (1:1) as the elution agent. Crystallization from methylene chloride/petroleum ether gives 2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]-5-(trifluoromethyl)benzimidazole of melting point 164°-166°.

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