Ahmed M. El-Agrody

Synthesis of halogen derivatives of benzo[h]chromene and benzo[a]anthracene with promising antimicrobial activities

The synthesis of novel 7-(4-halophenyl)-8,9-dihydro-7H-12-oxa-9,11-diaza-benzo[a]anthracene derivatives has been reported. The key intermediate 3-amino-9-chloro-1-(4-halophenyl)-1H-benzo[h]chromene-2-carbonitrile (3) was obtained by treating 4-halobenzylidenmalononitriles (1a-c) and ethyl 4-halobenzylidenmalonates (1d-f) with 4-chloro-1-naphthol (2) in ethanolic piperidine solution. Antimicrobial activity was shown for most of the synthesized compounds.

Heteroaromatization with 4-Hydroxycoumarin Part II: Synthesis of Some New Pyrano[2,3-d]pyrimidines, [1,2,4]triazolo[1,5-c]pyrimidines and Pyrimido[1,6-b]-[1,2,4]triazine Derivatives

A variety of novel [1,2,4]triazolo[1,5-c]pyrimidine-13-ones (4a-f) and (5b-d) could be obtained via reaction of 9-amino-7-(4’-chlorophenyl)-8,9-dihydro-8-imino-6H,7H-[1]benzopyrano[3`,4`:5,6]pyrano[2,3-d]pyrimidine-6-one (3) with a variety of reagents. Pyrano[2,3-d]pyrimidine-6-ones 5a, 8a-c and pyrimido[1,6-b][1,2,4]-triazine-3,14-dione (6) were also prepared. The antimicrobial activity of some of the synthesized compounds was tested.

Synthesis of Hydroxyquinoline Derivatives, Aminohydroxychromene, Aminocoumarin and Their Antibacterial Activities

Some new diaminochromenes (3a-f, 7a-c, and 10), 7-amino-4-aryl-coumarins (8a,b), 7-hydroxy-4-aryl-1,2-dihydroquinolines (9a-c) and 2-amino-7-hydroxy-4-(4-chlorophenyl)-4H-chromenes (16a-d) were synthesized viu Michael addition of different substituted aminonaphthol (1), aminophenol (6), resorcinol derivatives (15a-d), chloronaphthol (17) and 4-hydroxycoumarin (19) with a-cyanocinnamonitriles (2a-c) and ethyl α-cyanocinnamate (2d-f). 2-Acetylamino-7-amino-4-(4-chlorophenyl)-4H-chromene-2-carbonitrile (14) was obtained as a unique product via hydrazinolysis of ethoxymethyleneamino derivative (13). The formation of coumarins (8a,b) and quinolines (9a-c) were anomalous case. Structures of the titled compounds cited in this article were elucidated by spectrometric data (IR, 1 H NMR, 1 3 C NMR (APT) and EMS). All of the newly synthesized compounds were evaluated for antimicrobial activities, where 16b and 16c exhibited activity against staphylococcus aureus (ATCC 25923).

Synthesis, reactions and antimicrobial activities of 8-ethoxycoumarin derivatives.

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl3 gave β-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH2)2·H2O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a–c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.

Studies on the synthesis, in vitro antitumor activity of 4H-benzo[h]chromene, 7H-benzo[h]chromene[2,3-d]pyrimidine derivatives and structure–activity relationships of the 2-,3- and 2,3-positions

Some 4H-benzo[h]chromene and 7H-benzo[h]chromeno[2,3-d]pyrimidine derivatives were prepared as potential cytotoxic agents. The in vitro cytotoxic activity of the synthesized compounds was investigated in comparison with the well-known anticancer standard drugs Vinblastine, Colchicine, and Doxorubicin using MTT colorimetric assay. It was found that compounds 23, 15, 20, and 21 showed the highest anticancer activity against the three tumor cell lines MCF-7, HCT, and HepG-2, compared with Vinblastine and Colchicine, while compound 23 was the most active against HepG-2 as compared with Doxorubicin. We explored the SAR of 4H-benzo[h]chromenes with modification at the 2-,3- positions and 7H-benzo[h]chromeno[2,3-d]pyrimidine at 2,3-positions. The structure–activity relationship (SAR) study revealed that the antitumor activity on 4H-benzo[h]chromene and 7H-benzo[h]chromeno[2,3-d]pyrimidine derivatives were significantly affected by the lipophilicity (hydrophobic or hydrophilic), of the substituent at 2-,3- and 2,3-positions. Structures of these compounds were established on the basis of spectral data, IR, 1H NMR, 13C NMR, 13C NMR-DEPT, and MS data.

Synthesis, antitumor activity of 2-amino-4H-benzo[h]chromene derivatives, and structure–activity relationships of the 3- and 4-positions

Several 2-amino-4H-benzo[h]chromenes (3a–i) and (5a–h) were obtained by reaction of 4-chloro-1-naphthol (1) with α-cyanocinnamonitrile (2a–i) or ethyl α-cyanocinnamate derivatives (4a–h), respectively. Structures of these compounds were established on the basis of spectral data. The antitumor activity of the synthesized compounds was investigated in comparison with Vinblastine, Colchicine, and Doxorubicin well-known anticancer drugs, using MTT colorimetric assay. Among them, the compounds 5e, 3c, 5f, b, d, 3d, 5c, a were the most active against MCF-7, 5a against HCT-116 and 5a, 3e, a against HepG-2 as compared with the standard drug Vinblastine, while the compounds 5e, 3c, 5f, b, d, 3d, 5c, a, h, 3i, g, a, e were the most active against MCF-7, 5a, c, e, f, b, 3e, c, g, b, 5d, h, 3d, i, 5g against HCT-116, 5a, 3e, a, 5e, 3c, 5d, c, f, 3b, 5g, 3g, 5h against HepG-2 as compared with the standard drug Colchicine. The structure–activity relationships of the 3- and 4-positions were discussed.

Condensation of α-cyanocinnamonitriles with 6-bromo-2-naphthol: synthesis of pyrano (2,3-d)pyrimidine and pyrano(3,2-e) (1,2,4)triazolo(2,3-c)pyrimidine derivatives †

Naphthopyrans are synthesized by the reaction of cinnamonitriles with 6-bromo-2-naphthol; polysubstituted naph-thopyrimidines and naphthopyranotriazolopyrimidines are also prepared.

Synthesis and Biological Screening of 4-Benzyl-2H-phthalazine Derivatives

Preparation of 4-benzyl-2-substituted phthalazin-1-one derivatives 2-8 is reported. Condensation of 4-benzyl-1-chlorophthalazine (9) with a series of different nucleophiles gave 4-benzylphthalazin-1-ylamino derivatives (10-13 and 16) and 4-amino-2-[N′-(4-benzylphthalazin-1-yl)-hydrazino]-6-arylpyrimidine-5-carbonitriles (14a,b). Interaction of 9 with ambident anions was also studied. 5-Benzyl-6,6a,12-triazobenzo[a]-anthracen-7-one (15) is obtained from 9 and anthranilic acid derivatives. Treatment of 16 with (EtO)3CH/Ac2O under reflux afforded the corresponding ethoxymethylene derivative 17, while aqueous ammonium hydroxide treatment afforded carboxamide derivative 18. The structures of the newly synthesized derivatives were confirmed by their elemental analysis, IR, 1H NMR, 13C NMR and mass spectral studies. Antimicrobial activities of some selected compounds were also studied and some of these were found to exhibit promising effects against Gram-positive and Gram-negative bacteria and fungi.

Synthesis of 9-Methoxy and 9-Acetoxy-3-amino-1-(4-methoxyphenyl)- 1H-benzo[f]chromene-2-carbonitriles via 2-(Imino-piperidin-1-yl-methyl)- 3-(4-methoxyphenyl)acrylonitrile as Intermediate

Several new 1H-benzo[f]chromene derivatives (3aÐd) were prepared by the reaction of 7-substituted-2-naphthols (1a,b) with substituted α-cyano-4-methoxycinnamonitriles (2a,b) together with 2-(imino-piperidin-1-yl-methyl)-3-(4-methoxyphenyl)acrylonitrile (4) as intermediate. Also, the reaction of 1a,b with 4 without catalyst afforded 9-methoxy and 9-acetoxy- 3-amino-1-(p-methoxyphenyl)-1H-benzo[f]chromene-2-carbonitrile (3b,e). The reaction of 3a,b with different electrophilic and nucleophilic reagents afforded the 12H-7-oxa-8,10-diazabenzo[ a]anthracene derivatives 5, 9, 10 and 1H-benzo[f]chromene derivatives 6Ð8, 11.

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities.

Summary A series of 6,8-diiodocoumarin-3-N-carboxamides (4–11) were prepared. Treatment of ethyl 6,8-diiodocoumarin-3-carboxylate (1) with ethyl cyanoacetate/NH4OAc gave ethyl 2-(3-carbamoyl-6,8-diiodocoumarin-4-yl)-2-cyanoacetate (12) and 2-amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13), and treatment with acetone in the presence of NH4OAc or methylamine gave the ethyl 4-oxo-2,6-methano-2-methyl-3,4,5,6-tetrahydro-8,10-diiodobenzo[2,1-g]-2H-1,3-oxazocine-5-carboxylate derivatives 14a,b. All compounds were evaluated for their antimicrobial activity and the compounds 12–14a,b exhibited a pronounced effect on all tested microorganisms.