By Henk C. van der Plas (Eds.)

ISBN-10: 0120207745

ISBN-13: 9780120207749

Proven in 1960, Advances in Heterocyclic Chemistry is the definitive serial within the area--one of significant value to natural chemists, polymer chemists, and plenty of organic scientists. Written by means of confirmed specialists within the box, the great reports mix descriptive chemistry and mechanistic perception to yield an realizing of ways the chemistry drives the houses. Degenerate ring alterations of heterocycles are labeled as reactions during which a heterocyclic method is switched over into an identical heterocyclic method. This monograph covers an authoritative, finished review of a number of degenerate ring ameliorations in 5- and 6-membered heterocycles. It exhibits how via 15 N-labeled, 13 C-labeled, or selectively substituted compounds those degenerate rign changes will be found and the way many of the effects might be defined through the Addition Nucleophile, Ring starting, and Ring Closure [ANRORC] mechanism. one other major subject of the monograph is the incidence of degenerate ring changes.

Show description

Read or Download Degenerate Ring Transformations of Heterocyclic Compounds PDF

Best chemistry books

Get An Introduction Chemistry Of The Silicones PDF

An creation to the CHEMISTRY of the SILICONES via EUGENE G. ROCHOW study Laboratory, common electrical corporation long island JOHN WILEY SONS, INC. LONDON CHAPMAN corridor, constrained COPYRIGHT, 1946 through EUGENE G. ROCHOW AU Rights Reserved This booklet or any half thereof mustn't ever be reproduced in any shape with no the written permission of the writer.

Download e-book for kindle: Lyotropic Liquid Crystals and the Structure of Biomembranes by Stig (editor) Friberg

Washington 1976 1st. American Chemical Society. Advances in Chemistry sequence 152. Hardcover. eightvo, 156pp. , published textile. Residue of backbone label, establishment stamps on fore-edges, quantity stamp at decrease margin of 1 web page. reliable, no dj.

Additional info for Degenerate Ring Transformations of Heterocyclic Compounds

Example text

Ortho-iminomethylenebenzylcyanide (12), are involved in the formation of 3aminoisoquinoline (14). It can be suggested that the ratio 55 : 45 for the distribution of the 15N label over the exocyclic as well as ring nitrogen in 3-aminoisoquinoline may due to the occurrence of a scrambling process, taking place in the ring-labeled 13. 10). That 2-bromopyridine does not react according to an SN(ANRORC) mechanism, and 3-bromoisoquinoline only partly, can be understood in the light of NMR-studies on covalent amination with the parent azines: Pyridine does not form a covalent ␴-adduct with potassium amide, but isoquinoline gives ␴-adduct formation at C-1, forming 1-aminoisoquinolinide (72JA682; 73JOC1947).

33). On quenching, the ammonium cation, being a strong acid in this medium, not only neutralizes the amide ion, but also protonates the ring nitrogen of the 6-aminopyrimidinide (65) into the uncharged 6-amino-4-phenyl-1,6-dihydropyrimidine (66). This dihydropyrimidine can be converted into 6-amino-4-phenylpyrimidine (62), being labeled in the exocyclic amino group, or it may undergo an electrocyclic ring opening to form the intermediary acyclic aminodiazahexa-1,3,5-triene (67a, b). On recyclization of 67a, the ring-labeled 2-amino-4-phenyl-1,2-dihydropyrimidine (67) is formed, which is air-oxidized into ring-labeled 2-amino-4phenylpyrimidine (61).

Moreover, it was found that compound 40, being isolated from the reaction mixture obtained from the double-labeled 2-chloro-4-phenyl[1,3-15N]pyrimidine and the amide reagent, does not contain 15N-labeling! 26, the reaction follows the same pattern of ring opening, 4-amino-1-cyano-4phenyl-1-aza-1,3-butadiene (45) is formed as intermediate, which by loss of double 15N-labeled carbodiimide (aminocyanogen) is transformed into unlabeled 4-amino-4-phenyl-1-aza-1,3-butadiene (46). The aminoacrylonitrile 40 is formed from 46 by a Cannizzaro-type oxidation–reduction reaction.

Download PDF sample

Degenerate Ring Transformations of Heterocyclic Compounds by Henk C. van der Plas (Eds.)


by Mark
4.3

Rated 4.23 of 5 – based on 38 votes