반응 #702863

반응 방정식

HCl

cysteine hydrochloride

benzoyl chloride

potassium hydroxide

→

N,S-dibenzoylcysteine

수율 81.0%

용매

water

water

반응 조건

후처리

1. 1
   온도while cooling at 0°-5° C
2. 2
   workup.WAITwas continued for a further hour at room temperature
3. 3
   여과the precipitate was filtered off under suction
4. 4
   세척washed neutral with water
5. 5
   기타the product was recrystallized twice from methanol/water

실험 절차

63.0 g (0.4 mole) of cysteine hydrochloride were suspended in 400 ml of water, and 112.5 g (0.8 mole) of benzoyl chloride were added. A solution of 89.8 g (1.6 moles) of potassium hydroxide in 1 liter of water was added dropwise to the stirred mixture, while cooling at 0°-5° C. Stirring was continued for a further hour at room temperature, after which the mixture was rendered strongly acidic with aqueous 2N HCl, the precipitate was filtered off under suction and washed neutral with water, and the product was recrystallized twice from methanol/water. 106.3 g (81%) of N,S-dibenzoylcysteine of melting point 183°-185° C. were obtained; Rf=0.43 in system I, [α]D20 =-85.7° (c=1 in absolute ethanol).

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