Lactams imides

Heterocyclic Compounds (see also Anhydrides, Aziridines, Epoxides, Episulfides, Imides, Lactams, Lactones)... 

Amides. See also Imides Lactams Peptides infrared spectra, 519 table, 817 as intermediates in hydrolysis of nitriles, 815-816... 

The problem is apparently due to some residual aluminum that is hard to remove. If, however, the reduction is carried out in a iV-methylmorpholine solution, followed by addition of potassium tartrate, a pure product can be isolated. A -Methylmorpholine is a good solvent for reductions of various macromolecules with metal hydrides.In addition, the solvent permits the use of strong NaOH solutions to hydrolyze the addition complexes that form. Other polymers that can be reduced in it are those bearing nitrile, amide, imide, lactam, and oxime pendant groups. Reduction of polymethacrylonitrile, however, yields a product with only 70% of primary amine groups. Complete reductions of pendant carbonyl groups with LiAlH4 in solvents other than A -methyl-morpholine, however, were reported. Thus, a copolymer of methyl vinyl ketone with styrene was fully reduced in tetrahydrofuran. ... 

Division III. Heterocyclic compounds (Heterocyclic stem nuclei). The carbon atoms are joined in closed rings which include one or more other kinds of atoms as ring components. Anhydrides and imides of dibasic acids, as well as lactones, lactams, etc. are thus included in this division... 

Acylation of l,2,4-triazolo[l,5-c]quiiiazoliii-5-oiie (141) with ethyl chlo-roformate occurred at N6 to afford the 6-ethoxycarboiiyl derivative 142 (75CB3799) (Scheme 55). Tliis result indicates that the amide tautomer (lactam tautomer) 141 prevailed over the corresponding imidic acid tautomer (lactim tautomer). 

Tlie infrared spectra revealed the dominance of the 2-oxo (153) and 5-0X0 (157) structures (amide or lactam tautomers) over the 2-hydroxy (154) and the 5-hydroxy (192) structures (imidic acid or lactim tautomers)... 

Substituted azocine systems are much more stable than the parent compound, and 2-methoxy derivatives have been intensively examined. Starting from cyclohexa-1,4-diene (3), a [2 + 2] cycloaddition with chlorosulfonyl isocyanate, followed by removal of the chlorosulfonyl group, leads to the /3-lactam 4, which can be transformed by O-methylation with Meerwein s salt into the corresponding imidate. Monobromination with A-bromosuccinimide and subsequent treatment with base results in a methoxyazabicyclo[4.2.0]octatriene derivative, which spontaneously isomerizes to 2-methoxyazocine (5).13,14... 

Dicarbonsaure-imide ergeben als cyclische sekundare Carbonsaure-amide mit Hydri-den die verschiedensten Reduktionsprodukte, z. B. Hydroxy-lactame, Lactame, cyclische Amine, a>-Hydroxy-carbonsaureamide und a>-Amino-alkohole4. 

As in 10-55 hydrazides and hydroxamic acids can be prepared from carboxylic esters, with hydrazine and hydroxylamine, respectively. Both hydrazine and hydroxylamine react more rapidly than ammonia or primary amines (the alpha effect, p. 445). Imidates, RC(=NH)OR, give amidines, RC(=NH)NH2. Lactones, when treated with ammonia or primary amines, give lactams. Lactams are also produced from y- and 5-amino esters in an internal example of this reaction. 

Because of spatial limitations, only meso- and macrocycles possessing heteroatoms and/or subheterocycik rings ate reviewed in general, lactones, lactams, and cyclic imides have been excluded. In view of the delayed availability of some articles appearing in previous years, several have been incorporated. 

The use of cycloadditions for synthesizing medium-sized ring lactams is more or less restricted to the generation of seven-membered rings. The simplest method to generate azepinones seems to be the [6-1-1] reaction of a 1,6-dicar-boxylic acid chloride 148/152 and a phosphinimine 149, the in situ formed chloro enamine 150 underwent a Chapman rearrangement to give a cyclic imide 151/153 (Scheme 28)] [36]. 

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