Pyrido l ,2-a pyrimidines, chemistry

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 chemistry of the pyrido[l,2-a]pyrimidines has previously been reviewed by Mosby1, who found 43 references to this ring system while covering the literature up to 1957. Many of the early articles have been found to contain erroneous statements, and therefore these publications have also been included in the present work. 

Sec. II.A] CHEMISTRY OF PYRIDO[l,2-ti]PYRIMIDINES II. Preparation of Pyrido[l,2-a]pyrimidines... 

The chemistry of the pyrido[l,2-a]pyrimidines was reviewed in 1983 (83AHC241 85MI3). This earlier review covered the chemical literature through the first half of 1981 and surveyed 469 publications. In the last 12 years the appearance of another 500 papers and patents indicates the increasing interest in these compounds. 

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