Prepn of hydroxyethyl starches - using organic base catalyst useful as blood serum extenders

摘要

By using org. bases as the catalyst, starches or partially hydrolyzed starches (mol. wt. of anhyd. glucose unit = 162) are reacted with hydroxyethylating agents in the presence of alkalis to give hydroxyethyl starches (I). In an example, 0.2 g pyridine and 4.05 g sol. starch were dissolved in 30 ml. H2O contg. 0.5 g NaOH, mixed at 40 degrees during 4 hr. stirring with 3.7 ml ethylene oxide, stirred further 1 hr. neutralized with ion-exchange resins, and the filtrate distd. at 40-50 degrees and mixed with iso-PrOH to give 4 g (I) (DS = 0-78 and II/III = 3.89).