Acyclic imides. A general method of N-acylation of amides

Abstract

Many methods of monoacylation of primary amides were studied ; one, the sulphuric acid-catalysed reaction of amides with anhydrides at 100". w a s found to be very general. Several new acyclic imides were synthesised, including compounds as diverse as N-acetylvaleramide, N-valeryl-4-methylvaleramide, and 3a-acetoxy-N-acetylcholanamide. In two cases symmetrical imides related to the anhydride used were identified as minor by-products of the synthesis of mixed imides.WHEREAS cyclic imides such as succinimide and pht.ha1imide are well known and useful compounds, acyclic imides (A'-acylamides, R1*CO*NH*CO*RA) have been practically ignored. The reason is that while a way to make any desired imide can eventually be found, all attempts to devise a general method have fai1ed.lWe are trying to develop the photorearrangement of N-chloro-imides to 4-~hloro-imides,~ which are useful for conversion into lactones and pyrrolidone~,~ into a low and variable yields. Conversions, at least as measured by g.l.c., were improved by lowering the reaction temperature and changing the catalyst to acetyl bromide, but isolation of pure products on a preparative scale remained difficult and tedious. Results of these experiments are given in Table 1, nos. 7,9,10, 13, 17, and 23.The by-products of these reactions may often include not only nitriles, acids and tar, but also other imides.

Effect of deuteration on the metabolism and clearance of some pharmacologically active compounds—synthesis and in vitro metabolism of deuterated derivatives of dronedadrone

“…For the deuterated dronedarone derivatives completely labelled in the butyl side chains, 3b and 3f , the key per‐deuterated di‐n‐buylamine is commercially available, whereas for the compounds α‐deuterated to nitrogen in the side chains, that is, 3d , 3g and 3h , it was necessary to prepare the D 4 amine 5 (Scheme ). Butyryl chloride, 6 , and butanamide, 7 , were condensed under acidic conditions, using a modification of a literature procedure to yield the imide, 8 , which was reduced to 5 in good yield using lithium aluminium deuteride.…”

C-Glycosyl 1,2,4-triazoles: Synthesis of the 3-β-d-glucopyranosyl-1,5-disubstituted and 5-β-d-glucopyranosyl-1,3-disubstituted variants

“…of AcCl the presence of 1.2 equiv of NaH in THF, 28,29 2.5 equiv. of Bz2O with catalytic H2SO4 in CHCl3 at reflux temperature 30 ) incomplete conversion of the starting 1 was observed. Full transformation of 1 was achieved however, by using 5 equiv.…”

Anthraquinones: Versatile Organic Photocatalysts

“…Due the importance of diacylamines (or imides) as precursors for bioactive N-heterocycles, there are several protocols for their synthesis. [58,59] Most of these, however, suffer from low product yields, environmentally unfriendly solvents, and/or significant waste generation. [60] Itoh and colleagues reported a novel and practical preparation of diacylamines 59 from amides 58 with catalytic 2-CAQ in EtOAc and visible light at room temperature.…”