반응 #449328

반응 방정식

N-(tert-butoxycarbonyl)-3-methyl-L-valine

1-hydroxybenzotriazole

1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

N-ethylmorpholine

N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl ester

4-toluenesulphonic acid hydrate

→

N-[N-(tert-butoxycarbonyl)-3-methyl-L-valyl]-3-cyclopentyl-L-alanine benzyl ester

수율 61.4%

용매

dichloromethane

acetonitrile

반응 조건

후처리

1. 1
   workup.WAITthe solution was left
2. 2
   기타The white precipitate formed
3. 3
   추출The solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution
4. 4
   기타Evaporation and chromatography on silicagel
5. 5
   세척for the elution

실험 절차

1.54 g (4.44 mmol) of N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl ester and 2.53 g (13.32 mmol) of 4-toluenesulphonic acid hydrate were dissolved in 20 ml of acetonitrile and the solution was left to standat room temperature for 18 hours. The white precipitate formed was filteredoff and added to a mixture of 867 mg (3.75 mmol) of N-(tert-butoxycarbonyl)-3-methyl-L-valine, 557 mg (3.64 mmol) of 1-hydroxybenzotriazole, 793 mg (4.14 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 475 mg (4.13 mmol) of N-ethylmorpholine in 25 ml of dichloromethane and stirred at room temperature for 18 hours. The solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution and then driedover anhydrous magnesium sulphate. Evaporation and chromatography on silicagel using ethyl acetate/petrol (1:3) for the elution gave 1.06 g of N-[N-(tert-butoxycarbonyl)-3-methyl-L-valyl]-3-cyclopentyl-L-alanine benzyl ester as an off-white foam; MS: m/e 461 [M+H].

출처