1190604-26-2

Upstream product

• 616-34-2 methoxycarbonylmethylamine 
• 160056-97-3 (S)-Nα-(benzyloxycarbonyl)alanine hydroxamic acid 
• 1142-20-7 N-Cbz-Ala 

Relevant academic research and scientific papers

Ethyl 2-(tert-Butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma): An Efficient Reagent for the Racemization Free Synthesis of Ureas, Carbamates and Thiocarbamates via Lossen Rearrangement

Boc-Oxyma (Ethyl 2-(tert-butoxycarbonyloxyimino)-2-cyanoacetate) has been reported previously as an efficient coupling reagent for the synthesis of amides, peptides, esters, thioesters and hydroxamic acids. It is known for its excellent racemization suppression capability, and also as an environment friendly reagent as it generates only Oxyma as solid byproduct that can be recovered easily and recycled for the synthesis of the same reagent. In this update, we report a simple, efficient, environment friendly, chemoselective and racemization free method for the synthesis of ureas, carbamates and thiocarbamates from hydroxamic acids via Lossen rearrangement by using Boc-Oxyma. We have achieved racemization free di- and tri-peptidyl ureas with very good yield by using this protocol. A rigorous mechanistic investigation is also incorporated. (Figure presented.).

3,3-dichloro-1,2-diphenylcyclopropene (CPICL)-mediated synthesis of n α-protected amino acid azides and α-ureidopeptides

Rapid synthesis of acid azides via in situ generation of acid chlorides using CPICl as chlorinating agent from the corresponding Nα- protected amino acids is described. Also the conversion of acid azides into ureidopeptides through the Curtius rearrangement under ultrasonication is delineated. The mildness of the protocol renders the acid-sensitive substrates to afford the corresponding amino acid azides and ureidopeptides in good yields. Diphenylcyclopropenone has also been recovered from the reaction mixture and reused. Georg Thieme Verlag Stuttgart New York.

New and simple synthesis of acid azides, ureas and carbamates from carboxylic acids: Application of peptide coupling agents EDC and HBTU

Conversion of carboxylic acids into acid azides using peptide coupling agents, EDC and HBTU is described. The procedure is efficient, practical and applicable to a diverse range of carboxylic acids including N-protected amino acids. Using the same reagents, one-pot synthesis of ureas, dipeptidyl urea esters and carbamates from acids has also been achieved. The Royal Society of Chemistry 2010.

1-propanephosphonic acid cyclic anhydride (T3P) as an efficient promoter for the Lossen rearrangement: Application to the synthesis of urea and carbamate derivatives

The synthesis of hydroxamic acids starting from carboxylic acids employing 1-propanephosphonic acid cyclic anhydride (T3P) activation is described. Application of ultrasonication accelerates this conversion. Further, the T3P has also been employed to activate the hydroxamates, leading to isocyanates via the Lossen rearrangement. The isocyanates were trapped with suitable nucleophiles to afford the corresponding ureas and carbamates. Georg Thieme Verlag Stuttgart New York.

Application of carbodiimide mediated Lossen rearrangement for the synthesis of α-ureidopeptides and peptidyl ureas employing N-urethane α-amino/peptidyl hydroxamic acids

Application of the Lossen rearrangement to the synthesis of N-urethane protected α-peptidyl ureas and ureidopeptides is reported. The carbodiimide mediated rearrangement of N-Boc/Z/Fmoc protected α-amino/peptide hydroxamic acids into isocyanates and coupling of the latter with the amino acid esters/peptide esters have been accomplished in a single-pot to obtain good yields of urea products. Synthesis of the ureidoalanine derivatives via the hydroxamate derivatives of N-protected aspartic acid has also been carried out using the same procedure.