A new synthesis of N‐phenyl lactams

Abstract

The synthesis of N‐phenyl lactams by phase transfer oxidation of N,N‐(polymethylene) anilines with potassium permanganate is reported.

N-Aryl Lactams by Regioselective Ozonation of N-Aryl Cyclic Amines

“…Products were isolated by flash chromatography over silica gel ( R = 100), by eluting with a mixture of dichloromethane-ethyl acetate 9 : 1. 1 H-NMR, IR, and mass spectra of compounds 10 , 12 , and 14 were in accordance with literature data [15]. …”

“…Nevertheless, processes producing chlorinated waste should be replaced in order to comply with the recommendations of green chemistry. The latter has only an academic perspective at the present time; Markgraf and Stickney recently reported [15] a method for the preparation of N -phenyl-lactams based on the selective oxidation of cyclic tertiary amines with potassium permanganate under phase transfer catalysis conditions. The yield in N -phenyl-morpholin-3-one achieved from N -phenyl-morpholine was 45%.…”

Four‐Membered Heterocycles: Structure and Reactivity

“…Oxidations a of the nitrogen-atom (formation of b-lactams) have been performed with a RuO 2 -NaIO 4 mixture (Scheme 3.48) [ [101]. Transformations of azetidin-2-carboxylic acids and esters into of b-lactams using oxygen have been also reported [102].…”

Oxidation of diazenyl-protected N-heterocycles – a new entry to functionalized lactams

“…[1][2][3][4] Being modied by one of these protecting groups, oxidation of the amines with ring sizes from four to eight-membered rings have been reported. In most of the oxidation procedures, ruthenium catalysis has been used, but other methods including the use of manganese 5,6 as an oxidant or electrochemical oxidation 7 have also been described. Although the oxidation of N-derived cyclic amines to the corresponding lactams are known, several challenges still have not been mastered yet.…”

“…Although the oxidation of N-derived cyclic amines to the corresponding lactams are known, several challenges still have not been mastered yet. For the oxidation of four-membered Nheterocycles for example, only very few reactions based on Ncarbon- 5 and N-oxygen- [8][9][10][11] derived heterocycles have been shown so far. In addition, the oxidation of N-diazenylprotected cyclic heterocycles (piperidines), has been shown for only a couple of compounds producing the corresponding lactams in very low yields (up to 25%).…”