Iodolysis

Abstract

N-tert-Butyloxycarbonyl-S-trityl-l-cysteinyl-glycyl-l-glutamic acid di-tert-butyl ester (1.53 g, 2 mmol) and iodine (508 mg, 2 mmol) are dissolved in methanol (25 ml) and allowed to react at room temperature for one hour. The mixture is cooled in an ice-water bath and decolorized by the dropwise addition of a one molar solution of sodium thiosulfate in water. The mixture is diluted with water (50 ml) and the precipitated material filtered and dried. It is extracted with petroleum ether, three times (10 ml each time) [3]. The remaining solid is crystallized from ethyl acetate-hexane: 945 mg (91%); it melts at 150–152 °C. On elemental analysis correct values are obtained for C, H, N and S [4].