Conventional and Microwave‐Assisted Synthesis and Biological Activity Study of Novel Heterocycles Containing Pyran Moiety

Abstract

Under both conventional and microwave methods, 2‐amino‐4H‐pyran‐3‐carbonitrile derivative 1 was synthesized and reacted with different reagents. Thus, 2‐amino‐4H‐pyran‐3‐carbonitrile derivative was treated with chloroacetyl chloride, phenyl isocyanate, cyanoacetic acid, benzoyl chloride, triethyl orthoformate, acetic anhydride/H2SO4, arylidene malononitrile, urea, and/or p‐aminosulphaguanidine producing chloroacetamide, 3‐phenylurea, cyanoacetamide, N‐benzoylpyran, ethylformimidate, pyranopyrimidin‐4‐one, pyranopyridine, pyranopyrimidin‐2‐one, and pyranopyrimidin‐2‐imine derivatives, respectively. Meanwhile, compound 1 was reacted with ethyl bromoacetate, phenacyl bromide, phthalic anhydride, different aromatic amines, and/or acetic acid/H2SO4 to produce 5‐aminopyrano[2,3‐b]pyrrole‐6‐carboxylate, dihydropyrano[2,3‐b]pyrrole‐6‐yl‐(phenyl)methanone, 1,3‐dioxoisoindolinyl pyran, 1,4‐dihydropyridine, and 2‐hydroxy‐1,4‐dihydropyridine derivatives, respectively. On the other hand, when compound 1 was allowed to react with maleic anhydride and/or hydrazine hydrate, pyran‐4‐oxobut‐2‐enoic acid and 3‐aminopyranopyrazole derivatives were obtained, respectively. Reaction of pyran‐4‐oxobut‐2‐enoic acid with malononitrile under different conditions gave 2‐(furan‐2‐yl)‐4H‐pyran and 2‐(4H‐pyran‐2‐yl)‐1H‐pyrrole derivatives, while condensation of 3‐aminopyranopyrazole with benzaldehyde gave 1,4‐dihydropyrano[2,3‐c]pyrazol‐3‐yl‐1‐phenylmethanimine derivative. The newly synthesized compounds were characterized by the spectroscopic tools IR, 1H‐NMR, 13C‐NMR, MS, and elemental analysis. Some of these compounds have been screened in vitro for antimicrobial activity against different strains of bacteria and fungi and also were tested against two cancer cell lines: mammary gland breast cancer (MCF‐7) and colon cancer (HCT‐118).

Synthesis and biological activity of a new class of enaminonitrile pyrazole

“…Calcd. for C26H21N5O: C, 74.44; H, 5.05; N, 16.70;Found: C,74.28;H,5.14;N,pyrimidine (16) To a hot solution of compound 12 (3.2 g, 0.01 mol.) in ethanol (25 mL), hydrazine hydrate (0.5 mL, 0.01 mol.)…”

“…The pyrazole derivatives were dissolved in Sigma-Aldrich dimethyl sulfoxide "DMSO" with different concentrations "50 mg/ml". The inhibition zones were evaluated around each well at 37 O C after 24h "for fungi after 48h" controls using Sigma-Aldrich DMSO were adequately done [16][17].…”

An overview of recent advances in the catalytic synthesis of substituted pyrans

“…[24][25][26] Apart from these, they have varied importance in fields of dyes, [27,28] pH sensitizers, [29] semiconductors, [30,31] and materials. [32,33] Some biologically active compounds containing pyran scaffolds are depicted in Figure 2.…”

Conventional and microwave reactions of 1,3‐diaryl‐5,4‐enaminonitrile‐pyrazole derivative with expected antimicrobial and anticancer activities

“…Preparation of heterocyclic compounds by using microwave technique are previously reported, where microwave irradiation considered as one of the green chemistry techniques due to improve the yield, friendly environmental and reducing the reaction times …”