Synthesis
a6.Add H-Arg(Pbf)-OH, water 120L, THF in the reactor, adjust PH=8.5 with Na2CO3.
b6.Gradually add Fmoc-Osu (Fmoc-carbosulfinylsuccinimide), control the temperature 15-20 , PH=8-9 in order to complete the reaction of Arg(Pbf), and try to avoid the excess of Fmoc-Osu. Osu excess.
TLC plate tracking of the reaction, starting from the addition of Fmoc-Osu, reaction time 6 hours.
c6. Purification: extraction with petroleum ether/ethyl acetate (2:1); the aqueous phase was acidified with HCl to pH = 3 and stirred for 2 hours. Acidification temperature 0-10 ; add ethyl acetate to extract the product; wash with saturated brine to pH 6; anhydrous sodium sulfate drying, vacuum filtration to remove solids, filtrate concentration, concentrated under reduced pressure to get the solid, vacuum drying to get the product.
The purity of the product was 99.6%, the maximum single heterogeneity was 0.09%, and the L-type isomer was 0.15%.
