Synthesis and Antimicrobial Activity of Some New Heterocyclic Schiff Bases Derived from 2-Amino-3-formylchromone

Ibrahim, Magdy A.; El-mahdy, Kamelia M.

doi:10.1080/10426500802625594

Cited by 34 publications

(15 citation statements)

References 22 publications

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“…Thus, boiling carbonitrile 1 with thiosemicarbazide in absolute ethanol afforded pyrazole derivative 2 , via nucleophilic attack at C‐2 position with ring opening (intermediate A ) followed by cycloaddition into the nitrile group (intermediate B ) with concomitant proton transfer (Scheme ). Thiosemicarbazone derivative 3 , which was previously prepared from the direct condensation of 2‐aminochromone‐3‐carboxaldehyde ( 4 ) with thiosemicarbazide , was excluded based on the spectral data. The IR spectrum of compound 2 revealed characteristic absorption band at ṽ 1627 cm −1 , assignable to C═O benzoyl , the lower value of the carbonyl group may attribute to the strong hydrogen bonded with the amino and hydroxyl groups.…”

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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“…30 Heterocyclization of the -NH-C(=X)NHNH 2 functionality of 69e with some 1,2-bifunctional electrophiles as ClCOCOCl, ClCH 2 COCl, PhCOCH 2 Br, BrCH(CN) 2 and MeCOCO 2 Na leading to the appropriate 1,2,4-triazole derivatives has also been reported. A mixture of the aldehyde 1 and hydrazine hydrate on being heated with triethylammonium bisulfate (20 mol%) at 120 °C under solvent free conditions affords the bis-hydrazone 75.…”

Section: Methodsmentioning

confidence: 99%

Chemistry of 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes

Ghosh¹,

Chakraborty²,

Bandyopadhyay³

2016

Arkivoc

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“…Recently, this class of compounds have gained considerable interest because of their herbicidal [7,8], antimicrobial [9][10][11], anti-HIV [12] and anticancer activities [13,14]. On the other hand, the high biological activity of organophosphorus compounds, such as highly active anti-TMV activity [15], herbicides [16,17], insecticides [18,19], antitumor [20] and war gases, is well known.…”

Section: Introductionmentioning

confidence: 99%