Synthesis, structure characterization and biological evaluation of new 6,8-dichloro-2-methyl-4H-chromen-4-one derivatives

Abstract

KEYWORDSThe typical active methyl functionality of 6,8-dichloro-2-methyl-4H-chromen-4-one is utilized to obtain 2-styrylchromones, pyruvate ester and phthalide via reactions with aromatic carboxaldehydes, diethyl oxalate and phthalic anhydride respectively. The phthalide provides illustrative example to convert a heterocyclic compound to an aliphatic one via the effect of alcoholic sodium methoxide. Bromination and cycloaddition reactions of 2-styrylchromones afford vicinal dibromide and adducts respectively. This work presents to the art a typical example of heterocyclic systems transformations through the conversion of the starting chromone to coumarin under the influence of thionyl chloride followed by aqueous potassium hydroxide. Some heterocyclic systems like pyrazole, isoxazol and quinolinone are obtained from the target chromone by treatment with hydrazines, hydroxylamine hydrochloride and ammonium acetate respectively. Thiation of starting chromone interestingly affords a dithiated product instead of the expected monothiated one. Antibacterial and antifungal activities of some synthesized compounds have been screened.

Synthesis and Characterization of Some New Coumarins with in Vitro Antitumor and Antioxidant Activity and High Protective Effects against DNA Damage

“…Compounds 8a and 8b were formed when a mixture of compounds 3 and/or 4 was fused with ammonium acetate for 3h in the absence of solvent [41]. Proof of the structures of compounds 8a and 8b were based on spectral data.…”

Synthesis, Antibacterial, and Antiviral Evaluation of New Heterocycles Containing the Pyridine Moiety

“…In connection with our program aiming at the synthesis and biological evaluation of fused heterocycles , the authors' target, herein, was the preparation of furo[2,3‐ b ]pyridine, 1,2‐dihydropyrido[2,3‐ e ][1,3,4]thiadiazepine‐3(5 H )‐thione, and pyrido[2,1‐ c ][1,2,4]triazine. The key starting material 4‐(furan‐2‐yl)‐6‐(naphthalen‐1‐yl)‐2‐oxo‐1,2‐dihydropyridine‐3‐carbonitrile ( 1 ) has been synthesized via one‐pot multi‐component reaction of 1‐acetylnaphthalene, furfural, ethyl cyanoacetate, and ammonium acetate in ethanol.…”

Pyridine Compounds with Antimicrobial and Antiviral Activities

“…Salem et al [ 103 ] reported the synthesis of compound 231 by cyclisation of ethyl 2-(3-cyano-4-(furan-2-yl)-6-(naphthalen-1-yl)pyridin-2-yloxy)acetate in the presence of alcoholic KOH 10% at reflux and compound 232 by refluxing 4-(furan-2-yl)-2- hydrazinyl-6-(naphthalen-1-yl) nicotinonitrile with POCl 3 and PCl 5 , in a water bath ( Figure 25 ). Compounds 231 and 232 showed antiviral activity against rotavirus Wa strain and adenovirus type 7.…”