title: Synthesis of 1,1-Dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl (Bsmoc) protected N-methyl amino acids by reduction of Bsmoc-5-oxazoli-dinones and their use in peptide synthesis.
abstract: The synthesis of Bsmoc-N-methyl amino acids is presented. The first step involves p-toluenesulfonic acid (TsOH) catalysed condensation of a Bsmoc-amino acid with paraformaldehyde to furnish N-Bsmoc-5-oxazolidinone under MW irradiation. This intermediate is reduced to the corresponding N-methyl amino acid using triethylsilane (Et3SiH) and trifluoroacetic acid (TFA) at r.t. The N-methyl amino acids are converted into corresponding acid fluorides using diethylaminosulfur trifluoride (DAST) and employed as coupling agents in the synthesis of dipeptides. The peptide coupling was mediated by KOAt in CH2Cl2.
authors.affiliation: Peptide Research Laboratory, Department of Studies in Chemistry, Central College Campus, Bangalore University, Dr. B.R. Ambedkar Veedhi, Bangalore - 560 001, India.
authors.forename: Chennakrishnareddy
authors.initials: C
authors.lastname: Gundala
authors.forename: Subramanyam J
authors.initials: SJ
authors.lastname: Tantry
authors.forename: Shankar A
authors.initials: SA
authors.lastname: Naik
authors.forename: Vommina Venkata
authors.initials: VV
authors.lastname: Sureshbabu
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005459:Fluorides / Q000737:chemistry; D013058:Mass Spectrometry; D009904:Optical Rotation; D023303:Oxazolidinones / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis*; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D023303:Oxazolidinones; D010455:Peptides; D013876:Thiophenes; D005459:Fluorides