Reduced pyrazines reviews

Author(s) (Total References Cited) Year Published Reduced Pyrazines Reviewed Refs. 

Pratt (36) in 1957 published a comprehensive review which included reduced pyrazines (di- and tetrahydropyrazines, piperazines, and piperazinones), and the literature prior to 1957 is generally not further examined. 

This volume summarizes published pyrazine chemistry with emphasis on syntheses, properties, and reactions of pyrazines and pyrazine iV-oxides (Chapters 1-X). Treatment of theoretical aspects is minimal. Although not strictly relevant. Chapter XI is presented as a summary of earlier reviews and more recent literature of reduced pyrazines (including piperazines). The literature recorded in Beilstein to 1929 and Chemical Abstracts through 1978 (Volume 89) has been covered together with selected references to 1980. Whereas every reasonable effort has been made to incorporate most significant material, no attempt has been made to include all relevant data. Tables have been incorporated in the text to extend the range of examples. 

All possible reduced derivatives of pyrazine (I), and several of those of its benzo analogues quinoxaline (2) and phenazine (3), are known <84CHEC-I(3)157>. There are four dihydropyrazines, the 1,2-, 2,3-, 1,4- and 2,5-isomers, two tetrahydropyrazines, the 1,2,3,4- and 1,2,3,6-, and hexa-hydropyrazine or piperazine, the last of which is omitted in this review. The reduced quinoxalines are the 1,2- and 1,4-dihydro compounds and 1,2,3,4-tetrahydroquinoxaline. The only known reduced phenazine is 1,4-dihydrophenazine. 

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