Nitriles in Heterocyclic Synthesis: A New Synthesis of Some 4H-Naphthopyrans, 2H-Benzothiopyrans and Their Fused Derivatives

1992 ◽  
Vol 57 (7) ◽  
pp. 1570-1574 ◽  
Author(s):  
Abdel-Fattah A. Harb ◽  
Awatef M. El-Maghraby ◽  
Saoud A. Metwally
Keyword(s):  
Heterocyclic Synthesis ◽  
New Synthesis ◽  
Active Methylene

α,β-Unsaturated nitriles are versatile reagents and their chemistry has received considerable attention. The reactivity of cinnamonitriles I toward active methylene reagents has been extensively utilised for synthesis of pyranes.

Pyrazolo[3,4-b]pyridine in heterocyclic synthesis: synthesis of new pyrazolo[3,4-b]pyridines, imidazo[1',2':1,5]pyrazolo[3,4-b]pyridines, and pyrido[2',3':3,4]pyrazolo[1,5-a]pyrimidines

2007 ◽  
Vol 85 (9) ◽  
pp. 592-599 ◽  
Author(s):  
Mohamed A.M Gad-Elkareem ◽  
Azza M Abdel-Fattah ◽  
Mohamed A.A Elneairy
Keyword(s):  
Pyridine Derivative ◽  
Pyridine Derivatives ◽  
Heterocyclic Synthesis ◽  
Acetyl Acetone ◽  
Active Methylene

Pyrazolo[3,4-b]pyridine derivatives 7 and 9 were synthesized via the reaction of 3-amino-1H-pyrazolo-[3,4-b]pyridine derivative 2 with ω-bromoacetophenones. Reaction of 7 and 9 with Ac2O afforded the imidazo[1',2':1,5]py razolo[3,4-b]pyridine derivative 8 and pyrazolo[3,4-b]pyridine derivative 10, respectively. Reaction of 2 with chloroacetonitrile followed by DMF-DMA gave imidazo[1',2':1,5]pyrazolo[3,4-b]pyridines 4 and 5, respectively. Acetyl acetone and 1,1-dicyano-2,2-dimethylthioethene were reacted with 2 to afford the pyrido[2',3':3,4]pyrazolo-[1,5-a]-pyrimidines 11 and 14, respectively. Also, 2 reacted with DMF-DMA to yield the formamidine 15, which in turn, reacted with active methylene reagents, yielding the corresponding pyrido[2',3':3,4]pyrazolo[1,5-a]pyrimidines 18 and 23a-23d.Key words: 1H-pyrazolo[3,4-b]pyridines, imidazo[1',2':1,5]pyrazolo[3,4-b]pyridines, pyrido[2',3':3,4]pyrazolo[1,5-a]pyrimidines.

Activated Nitriles in Heterocyclic Synthesis: A New Synthesis of 3-Furan-2-ylidene- and 1-Thiophen-2-ylidene-3,6-dihydropyridine Derivatives

Heterocycles ◽  
1984 ◽  
Vol 22 (12) ◽  
pp. 2829 ◽  
Author(s):  
Galal Eldin Hamza Elgemeie ◽  
Ebtisam Abdel Aziz Hafez ◽  
Galal Abdel Moein Nawar ◽  
Mohamed Hilmy Elnagdi
Keyword(s):  
Heterocyclic Synthesis ◽  
New Synthesis ◽  
Dihydropyridine Derivatives
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