title: Amino-acids condensations in the preparation of N alpha-9-fluorenylmethyloxycarbonylamino-acids with 9-fluorenylmethylchloroformate.
abstract: Synthesis of N alpha-9-fluorenylmethyloxycarbonyl (Fmoc) amino-acids by reaction of free amino-acids (glycine and alanine) with 9-fluorenylmethylchloroformate leads to formation of small amounts of Fmoc-dipeptide which are difficult to eliminate by crystallization. The alternative way to prepare Fmoc-amino-acids by reacting the Fmoc-chloride first with sodium azide and then with the free amino-acid eliminates this side reaction, at least for glycine and alanine.
mesh_terms: D000596:Amino Acids; D055598:Chemical Phenomena; D002621:Chemistry; D005449:Fluorenes; D009842:Oligopeptides / Q000138:chemical synthesis*; D012995:Solubility
chemical_list: D000596:Amino Acids; D005449:Fluorenes; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D009842:Oligopeptides