THE AMINE GROUP PROTECTION OF L-CYSTEINE AND L-VALINE THROUGH THE FORMATION OF FORMAMIDE

Abstract

The reactions of amine group protection of L-valine and L-cysteine have been accomplished in this research with formic acid protecting agent to form formamide L-valine and formamide L-cysteine respectively. This two formamides of the amino acid would be used to synthesize 6-amino penicillanic acid (6-APA), a very important key intermediate for a new β-lactame antibiotic. The reaction was carried out in a round bottom flask of a refluks set at 50-60oC for 60-90 minutes. After the time was over, the liquid excess was separated employing Buchii rotary evaporator and then it was recrystalized with ethanol for pure crystal. The crystal produced from L-valine treatments melted at 153-154oC, and those from L-cysteine melted at 129-131oC. The crystals each gave one mark on a 60F254 silica gel TLC plate and their IR spectrum each indicated that the reactions of those was successfull to be done, and each formed formamide L-valine and formamide L-cysteine respectively.