Ethyl Tosyl-L-isoleucylg1ycinate.-A solution of tosyl-Lisoleucyl chloride (prepared from 2.9 g. of tosyl-L-isoleucine and-phosphorus pentachloride) in r5 ml. of anhydrous ether was added slowly to a suspension of 2.5 g. of ethyl glycinate hydrochloride and 3.5 ml. of triethylamine in 50 ml. of anhydrous ether and the mixture was allowed to stand at room temperature for 12 hours. The white precipitate was filtered off and washed with ether. After trituration with water to remove the triethylamine hydrochloride, 3.34 g. of product, m.p. 159-160°, was obtained; yield 89%. Another 0.25 g., m.p. 152-154', was afforded by extraction of the ether filtrate successively with water, dilute HCl, dilute aqueous KHCO, and water, followed by removal of the ether zn vacuo. Recrystallization of the second crop from ethanol raised the m.p. to 158-160". For analysis, the tosyl dipeptide ester was recrystallized twice from ethanol and then melted a t 160-161".

No abstract

No abstract

No abstract

No abstract