Under similar conditions, the yields of urea formed by isocyanates derived from esters of glutamic acid, glycine, and the branched leucine are 90, 80, and 45-50%, respectively. Reaction with water was stopped after one hour by addition of the much more reactive bensylamine forming a benzyl urea. Actil ation of the isocyanate group disappears when t8he carbonyl is separated by more than one methylene group. Isocyanates derived froin ...
![ethyl 2-[(1-ethoxycarbonyl-3-methylsulfanyl-propyl)carbamoylamino]-4-methylsulfanyl-butanoate结构式](https://image.chemsrc.com/caspic/304/70779-91-8.png)
