Studies in the triazine series including a new synthesis of 1:2:4-triazines

Laakso, Perttu V.; Robinson, R. A.; Vandrewala, H.P.

doi:10.1016/0040-4020(57)85014-5

Cited by 91 publications

(21 citation statements)

References 15 publications

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“…Similarly, quinolinylpyrazole 7 and 1,2,4‐triazinylpyrazole 8 were efficiently synthesized from treating carbonitrile 1 with 7‐chloro‐4‐hydrazinoquinoline and 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine in refluxing ethanol (Scheme ). Compounds 7 and 8 gave red color with FeCl 3 solution.…”

Section: Resultsmentioning

confidence: 99%

Ring Opening and Recyclization Reactions with Chromone‐3‐carbonitrile

Ibrahim

El-Kazak

2019

Journal of Heterocyclic Chem

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Chemical transformations of chromone‐3‐carbonitrile (1) with some substituted hydrazines, namely, thiosemicarbazide, S‐methyl/benzyldithiocarbazate, 7‐chloro‐4‐hydrazinoquinoline, and 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine, led to substituted pyrazoles 2, 5–8. Ring opening of carbonitrile 1 followed by recyclization with 3‐amino‐1,2,4‐triazole and 2‐aminobenzimidazole gave triazolo[1,5‐a]pyrimidine 9 and pyrimido[1,2‐a]benzimidazole 10, respectively. Treatment of carbonitrile 1 with some heterocyclic amines produced 2‐amino‐3‐substituted‐chromones 11 and 12. The novel 3‐hydroxychromeno[4,3‐b]pyrazolo[4,3‐e]pyridin‐5(1H)‐one (13) was efficiently synthesized from the ring conversion of carbonitrile 1 with cyanoacetohydrazide. A mixture of chromeno[2,3‐b]naphthyridine 14 and chromeno[4,3‐b]pyridine 15 was obtained from base catalyzed transformation of carbonitrile 1 with malononitrile dimer. A diversity of novel annulated chromeno[2,3‐b]pyridines 16–22 was also synthesized. Chromeno[2,3‐b]pyrrole‐2‐carboxylate 23 was obtained from the reaction of carbonitrile 1 with ethyl chloroacetate. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data.

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Section: Resultsmentioning

confidence: 99%

Ring Opening and Recyclization Reactions with Chromone‐3‐carbonitrile

Ibrahim

El-Kazak

2019

Journal of Heterocyclic Chem

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“…On the other hand, the reaction of carboxaldehyde 1 with 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine ( 16 ) in boiling acetic acid did not give the corresponding hydrazone 17 but afforded directly the triazinylpyrazole derivative 18 linked benzofuran moiety through a carbonyl group (Scheme ). The same product was obtained when the reaction occurred in boiling ethanol containing triethylamine.…”

Section: Resultsmentioning

confidence: 99%

Chemical Reactivity of 4,9‐Dimethoxy‐5‐oxo‐5H‐furo[3,2‐g]chromene‐6‐Carboxaldehyde Toward Some Nucleophilic Reagents

El‐Gohary

Ibrahim

El‐Sawy

et al. 2016

Journal of Heterocyclic Chem

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The chemical reactivity of 4,9‐dimethoxy‐5‐oxo‐5H‐furo[3,2‐g]chromene‐6‐carboxaldehyde (6‐formylkhellin) (1) was studied toward a diversity of nitrogen nucleophilic reagents. Reaction of carboxaldehyde 1 with some primary amines and heterocyclic amines afforded the corresponding Schiff bases. Also, the reactivity of carboxaldehyde 1 was studied toward some hydrazine derivatives, namely 7‐chloro‐4‐hydrazinoquinoline, 3‐hydrazino‐5,6‐diphenyl‐1,2,4‐triazine, N4‐phenylthiosemicarbazide, and S‐benzyldithiocarbazate. 6‐Formylkhellin (1) underwent ring transformation upon treatment with hydroxylamine hydrochloride producing 5‐hydroxy‐4,9‐dimethoxy‐7‐oxo‐7H‐furo[3,2‐g]chromene‐6‐carbonitrile (22). Some pyrimidine, [1,2,4]triazolo[4,3‐a]pyrimidine, tetrazolo[1,5‐a]pyrimidine, and diazepine derivatives linked benzofuran were efficiently synthesized. Reaction of carboxaldehyde 1 with a variety of 1,4‐binucleophiles produced furochromone‐fused benzodiazepine, pyridotriazepine, benzoxazepine, and benzothiazepine derivatives. Some unsymmetrical thiocarbohydrazones were also synthesized. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data.

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“…(9) mp 157'1. After cooling, the mixture was cautiously poured onto 500 g of ice with vigorous stirring.…”

Section: 6-diaryl-as-triazin-3(zh)-ones (Vi and Vi1mentioning

confidence: 99%