Dibutylphosphate (DBP) mediated synthesis of cyclic N,N′-disubstituted urea derivatives from amino esters: a comparative study
作者:Sumit K. Agrawal、Manisha Sathe、A.K. Halve、M.P. Kaushik
DOI:10.1016/j.tetlet.2012.08.083
日期:2012.11
The N,N′-disubstituted urea derivatives such as amino acid hydantoins and dihydrouracil derivatives were prepared starting from natural and unnatural amino acid esters using dibutylphosphate (DBP). During the attempted synthesis of N-heterocycles with larger than six-membered rings containing the N,N′-disubstituted urea functionalities, three unexpected products namely squamolone, N-methyl pyrrolidine-2-one