By A.R. Katritzky, A.J. Boulton (Eds.)
(from preface)Volume 26 includes 3 chapters. C.A.Ramsden reports heterocy-clic betaines derived from 6-membered heteroaromatic jewelry. those compounds were intensively studied over the last 10 years and feature no longer formerly been comprehensively reviewed. O. Meth-Cohn and B. Tarnowski summarize the chemistry of the thiocoumarins, a a little ignored crew of heterocycles. ultimately, W. Friedrichsen has reviewed the chemistry of the benzo[r]furans which, in contrast to the aza and thia analogs, haven't formerly been thought of during this sequence. the following back we've got a gaggle of compounds the chemistry of which has complex significantly during the last decade.
Read or Download Advances in Heterocyclic Chemistry, Vol. 26 PDF
Best chemistry books
Speedily expanding curiosity within the difficulties of pollution and source-receptor relationships has resulted in an important enlargement of data within the box of atmospheric chemistry. as a rule the chemistry of atmospheric hint ingredients is ruled by means of the oxygen content material of the ambience. Upon coming into the ambience in a kind of diminished nation, hint components are oxidized through numerous pathways and the generated items are frequently precursors of acidic compounds.
- Applications of Organometallic Chemistry in the Preparation and Processing of Advanced Materials
- Physical Functions of Hydrocolloids (Advances in Chemistry 025)
- Reviews in Computational Chemistry, Volume 15
- Evolution - fact or fable
- Chemistry and Technology of Lubricants, Third Edition
- The Rudolf Report: Expert Report on Chemical and Technical Aspects
Extra info for Advances in Heterocyclic Chemistry, Vol. 26
Chem. 37, 1592 (1972). 17' I" Sec. B] 49 HETEROCYCLIC BETAINES 14. I ,2,3-Benzotriazinium-4-aminides (269) NR' NHAr NHAr Menschutkin alkylation of 4-arylamino- 1,2,3-benzotriazines (270) in ethanol occurs at the 2-position. The benzotriazinium iodides (271) so formed are readily deprotonated by base giving the betaines (269; R' = alkyl, R2= aryl). In the presence of sodium ethoxide, alkylation of benzotriazines 270 occurs at positions 2 and 3. The bright red betaines 269 form salts with dilute hydrochloric acid and are dealkylated by hot ethanolic potassium hydroxide.
Perkin 2, 1304 (1977). Sec. A] 25 HETEROCYCLIC BETAINES 4. Thiopyryliun~-3-olates (132) m& R R R R 8 (135) exo-syn (136) endo-syn Thiopyran-3(6H)-ones (133; R = H or Me) are converted into 3hydroxythiopyrylium perchlorates (134; R = H or Me) by triphenylmethyl perchlorate. Deprotonation of these salts (134) by tertiary base did not liberate the thiopyrylium-3-dates (132) but instead gave dimeric products (135 and 136) in high yield. Evidence for the transient formation of the mesomeric betaines (132) is provided by the appearance of a greenishyellow coloration which rapidly fades.
2. 217 3. 4-(Pyridinium)phenolates(297) These compounds (297) have interesting thermochromic and solvatochromic effects. ''' Dramatic changes are also observed when the solvent polarity is 'lo ''I *'' 'I3 'I4 '15 'Ih 'I' W. Schneider, W. Dijhling. and R. Cordua. Bcr. rch. Chrrn. Ges. B 70. 1645 (1937). K. Dimroth. C. Reichardt, and A. Schweig, Jusrus Liehigs Ann. Chenz. 669, 95 (1963). G . Doleschall and K. Lempert, Tetraliedron 29, 639 (1973). G . Doleschall and K. Lempert, Tetraliedron 32, 1735 (1976).