Syntheses of 3,4,7‐triazaacenaphthylene and pyrido[3,4,5‐de]cinnoline derivatives

Convenient synthesis of some new substituted pyrazolyl-1,3,4-oxadiazoles and pyrazolyl-1,2,4-triazoles

“…Several 1,2,4-triazole derivatives show anti-inflammatory [18], vasodilatory [19] and psychotropic properties [20]. Recently, our interest in the synthesis of various substituted heterocyclic systems, which could be adapted for the preparation of small libraries, has been the subject of several publications from our laboratory [21][22][23][24][25][26][27][28][29][30][31]. During our investigation, we have found that acid hydrazides can be used as useful intermediates leading to the formation of several heterocycles of potential biological activity such as 1,2,4triazoles, 1,3,4-oxadiazoles and 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines [23,32].…”

Dimethylformamide dimethyl acetal as a building block in heterocyclic synthesis

“…The latter (107a,b) can also be prepared by treatment of (108a,b) with DMFDMA to give the corresponding enamines (109a,b) followed by coupling with diazonium salt of m-nitroaniline in sodium hydroxide to give the corresponding aldehyde derivatives (110a,b) followed by treatment with hydrazine hydrate and aromatic amines (Scheme 19) [73].…”

Enamines and Dimethylamino Imines as Building Blocks in Heterocyclic Synthesis: Reactions of DMF‐DMA Reagent with Different Functional Groups

“…Then, pyrido pyridazine derivatives ( 93 ) were obtained by intramolecular cyclization of enamine ( 91 ) with amines derivatives (hydrazine hydrate, aniline, 2‐aminopyridine et al.) [34] …”