Hermecz thiazines

The second chapter (A. Schmidt, Clausthal, Germany) provides a concise review of heterocyclic mesomeric betaines and their analogs as found in natural products. Finally, L Hermecz (Budapest, Hungary) provides part two of his survey of pyrido-oxazines, pyrido-thiazines, pyrido-diazines and their benzologs. This encompasses a large variety of heterocycles, many of which are of increasing importance because of their physiological activity. Much of this material has not been reviewed for decades and the subject has advanced enormously in this period. 

The final chapter by Istvan Hermecz (Chinoin, Ltd., Budapest, Hungary) deals with bicyclic systems containing one ring junction nitrogen and one heteroatom and their benzologs, i.e. pyrido-oxazines, pyrido-thiazines, pyrido-pyridazines, pyrido-pyrazines, pyrido-pyrimidines and their analogs. Much of this material has not been reviewed for forty years, during which time immense advances have occurred. 

Dr. Istvan Hermecz (Chinoin, Budapest, Hungary) covers the chemistry of pyrido[l,2-6][l,2]oxazines, -thiazines, and -pyridazines and their benzo-logs, compound classes that have not previously been reviewed but which in recent years have shown increasing significance with regard to their biological and other properties. This forms the first installment of a set of three chapters the subsequent installments in later volumes of our series will deal with (i) [l,2-c]-fused 1,3-oxazines, 1,2-thiazines, and pyrimidines (ii) [2,l-6]-fused analogs and (iii) fused 1,4-oxazines and 1,4-thiazines. 

The chemistry of l,2,4-triazolo[4,3-a]pyrimidines is covered in the first installment of a general treatment of 1,2,4-triazolopyrimidines (isostears of purines) by Professor M. A. E. Shaban and Dr. A. E. A. Morgaan (Alexandria University, Egypt). The final installment of Dr. I. Hermecz s (CHINOIN Ltd., Hungary) five-part-series on pyrido-oxazines, -diazines, and -thiazines comprises Chapter 4 of the present volume and covers ben-zologs of pyrido[l,2,-a]pyrimidines. Parts I through IV appeared in Volumes 69-72 of our series. 

The next chapter continues the series by Dr. I. Hermecz (Budapest, Hungary) on the chemistry of pyridooxazines and -thiazines. This chapter, Part IV of the series, deals with the chemistry of pyrido[2,l-6][l,3] oxazines and [l,3]thiazines together with their benzologs. The first three parts of the series comprised Part I in Volume 69 on pyrido[l,2-b]-l,2-oxazines, -1,2-thiazines, and -pyridazines and their benzologs Part II in Volume 70 on pyrido[l,2-c]-l,3-oxazines, -1,3-thiazines, and -pyrimidines and their benzologs and Part III in Volume 71 on pyrido[2,l-c]-l,4-oxazines, -1,4-thiazines, and -pyrazines and their benzologs. 

Hermecz, I., Chemistry of Benzologs of Pyrido[l, 2-a]pyrimidines Part V of Series on Pyrido-oxazines, -diazines, and-thiazines, 73, 177. 

Hermecz, I., Recent Development in the Chemistry of Pyrido-oxazines, Pyrido-thiazines, Pyrido-diazines and Their Benzologs Part I, 84, 221. 

The next chapter represents the third in a series of articles by Dr. I. Hermecz on the chemistry of pyrido-oxazines, -thiazines, and -diazines. Part I, in Volume... 

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