1190604-27-3Relevant academic research and scientific papers
Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate-mediated lossen rearrangement: Single-pot racemization-free synthesis of hydroxamic acids and ureas from carboxylic acids
Thalluri, Kishore,Manne, Srinivasa Rao,Dev, Dharm,Mandal, Bhubaneswar
, p. 3765 - 3775 (2014/05/20)
Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate (4-NBsOXY) mediated Lossen rearrangement and its application for the synthesis of ureas is demonstrated. Required hydroxamic acids for the Lossen rearrangements were synthesized from carboxylic acids using the same reagent. Finally, reaction of an amine with the produced isocyanate resulted in urea. Good yields without racemization were achieved under milder and simpler reaction conditions. Reactions are compatible with common N-protecting groups, such as Boc, Fmoc, Cbz, and benzyl, as well as various OH protecting groups, such as tBu and Bzl. Conversion from carboxylic acid to urea is achieved in one pot. Most importantly, byproducts Oxyma [ethyl 2-cyano-2-(hydroxyimino)acetate] and 4-nitrobenzenesulfonic acid can be recovered easily and can be recycled to prepare the reagent. Thus, the method is environmentally friendly and cost-effective.
Iodine-accelerated synthesis of Nα-urethane protected amino/peptide hydroxamic acids from amino/peptide thioacids
Panguluri, Nageswara Rao,Narendra,Sureshbabu, Vommina V.
, p. 1430 - 1435 (2015/01/08)
A facile and mild synthesis of Nα-protected amino/peptide hydroxamic acids is accomplished from the corresponding Nα-protected amino/peptide thioacids using I2, 1 -hydroxybenzotriazole (HOBt) and NH2OH at RT. The protocol can be extended to bifunctional as well as sterically hindered amino acids, to afford amino/peptide hydroxamic acids in good yields.
1-propanephosphonic acid cyclic anhydride (T3P) as an efficient promoter for the Lossen rearrangement: Application to the synthesis of urea and carbamate derivatives
Vasantha, Basavalingappa,Hemantha, Hosahalli P.,Sureshbabu, Vommina V.
experimental part, p. 2990 - 2996 (2010/10/21)
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
Narendra,Chennakrishnareddy, Gundala,Sureshbabu, Vommina V.
supporting information; experimental part, p. 3520 - 3526 (2010/01/06)
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.
