反応 #63756

反応方程式

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

溶媒

—

alcohol

water

反応条件

後処理

1. 1
   温度while cooling with ice
2. 2
   workup.WAITthe mixture is left
3. 3
   温度at reflux overnight
4. 4
   その他subsequently evaporated to dryness in vacuo
5. 5
   workup.DISSOLUTIONThe residue is dissolved in 1.5 l of methylene chloride
6. 6
   洗浄The solution is washed firstly with 200 ml of 1.5N sodium hydroxide solution
7. 7
   乾燥3 x with 700 ml of water, dried over sodium sulphate
8. 8
   その他evaporated in vacuo
9. 9
   その他The crude product is purified on 360 g of silica gel with ethyl acetate/methylene chloride (1:1) as the elution agent
10. 10
    その他Crystallization from methylene chloride/petroleum ether

実験手順

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°.

出典