TY - JOUR
T1 - Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate-mediated lossen rearrangement
T2 - Single-pot racemization-free synthesis of hydroxamic acids and ureas from carboxylic acids
AU - Thalluri, Kishore
AU - Manne, Srinivasa Rao
AU - Dev, Dharm
AU - Mandal, Bhubaneswar
PY - 2014/5/2
Y1 - 2014/5/2
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84899872918&partnerID=8YFLogxK
U2 - 10.1021/jo4026429
DO - 10.1021/jo4026429
M3 - Article
C2 - 24678821
AN - SCOPUS:84899872918
SN - 0022-3263
VL - 79
SP - 3765
EP - 3775
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
IS - 9
ER -