Design and synthesis of novel thiophenecarbohydrazide, thienopyrazole and thienopyrimidine derivatives as antioxidant and antitumor agents

2-Amino-5-acetyl-4-methyl-thiophene-3-carboxylic acid ethyl ester (1) and 5-acetyl-2-amino-4-methylthiophene-3-carbohydrazide (2) were synthesized and used as starting materials for the synthesis of new series of 1-(5-amino-4-(3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3a), 1-(5-amino-4-(4-chloro-3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3b), 1-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl)pyrazolidine-3,5-dione (4), (Z)-N'-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl) formohydrazonic acid (5a), (Z)-ethyl-N'-4-methyl-2-amino-5-acetylthiophene-3-carbonylformo hydrazonate (5b), 6-acetyl-3-amino-2,5-dimethylthieno[2,3-d]pyrimidin-4(3H)-one (8), 5-methyl-3-amino-2-mercapto-6-acetylthieno [2,3-d]pyrimidin-4(3H)-one (10) and 5-methyl-6-acetyl-2-thioxo-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-one (12) as potential antioxidant and antitumor agents. Pharmacological tests showed that compounds 6a, 6b, 8, 10 and 12 exhibited significant antitumor and antioxidant activity.     

Imidazo[1,2-a]-s-triazine nucleosides. Synthesis and antiviral activity of the N-bridgehead guanine, guanosine, and guanosine monophosphate analogues of imidazo[1,2-a]-s-triazine.

The first chemical synthesis of 2-aminoimidazo[1,2-a]-s-triazin-4-one (8), the corresponding nucleoside and nucleotide, and certain related derivatives of a new class of purine analogues containing a bridgehead nitrogen atom is described. Condensation of 2-amino-4-chloro-6-hydroxy-s-triazine (2) with aminoacetaldehyde dimethyl acetal followed by the ring annulation gave the guanine analogue 8. A similar ring annulation of 4-(2,2-dimethoxyethylamino)-s-triazine-2,6-dione (5) gave imidazo[1,2-a]-s-triazine-4,6-dione (9). Direct glycosylation of the trimethylsilyl derivative of 8 with 1-O-acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose in the presence of stannic chloride, followed by debenzoylation, gave the guanosine analogue 2-amino-8-(beta-D-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one (12b), which on deamination gave the xanthosine analogue 13. Phosphorylation of 12b gave 2-amino-8-(beta-D-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one 5'-monophosphate (II). The anomeric configuration has been determined unequivocally by using NMR of the 2',3'-O-isopropylidene derivate 10 and the site of ribosylation has been established by using 13C NMR spectroscopy. These compounds were tested against type 1 herpes, type 13 rhino, and type 3 parainfluenza viruses in tissue culture. Moderate rhinovirus activity was observed for several compounds at nontoxic dosage levels.     

Synthesis and antitumor activity of certain 3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4-f]-1,2,4-triazines related to formycin prepared via ring closure of a 1,2,4-triazine precursor

Several 3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4-f]-1,2,4-triazines related to formycin were prepared and tested for their antitumor activity in cell culture. Dehydrative coupling of 3-amino-6-hydrazino-1,2,4-triazin-5(4H)-one (5) with 3,4,6-tri-O-benzoyl-2,5-anhydro-D-allonic acid (6a) and further ring closure of the reaction product (7) provided 6-amino-3-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,2,4-triazolo[3,4- f]-1,2,4-triazin-8(7H)-one (8). Condensation of 5 with 3,4,6-tri-O-benzoyl-2,5-anhydro-D-allonic acid chloride (6b), followed by ring annulation, also gave 8 in good yield. Debenzoylation of 8 furnished the guanosine analogue 6-amino-3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4-f]-1,2,4-triazin -8(7H)-one (4b). Thiation of 8 with P2S5, followed by debenzoylation of the thiated product (11a), afforded 6-amino-3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4-f]-1,2,4-triazin -8(7H)- thione (11b). Methylation of the sodium salt of 11a gave the 8-methylthio derivative (10), which on ammonolysis furnished 6,8-diamino-3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4-f]-1,2,4-triazine (9). Diazotization of 10 with tert-butyl nitrite (TBN) and SbCl3 in 1,2-dichloroethane gave the corresponding 6-chloro derivative (12a). Reaction of 10 with TBN in THF in the absence of a halogen source gave 8-(methylthio)-3-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,2,4- triazolo[3,4-f]-1,2,4-triazine (12b). Ammonolysis of 12b gave the azaformycin A analogue 8-amino-3-beta-D-ribofuranosyl-1,2,4- triazolo[3,4-f]-1,2,4-triazine (3), which on deamination afforded 3-beta-D-ribofuranosyl-1,2,4-triazolo[3,4- f]-1,2,4-triazin-8(7H)-one (4a). The azaformycin A analogue (3) showed pronounced inhibitory effects against L1210, WIL2, and CCRF-CEM cell lines with ID50 values ranging from 5.0 to 7.3 microM.     

Adenosine deaminase inhibitors. Synthesis and biological evaluation of (+/-)-3,6,7,8-tetrahydro-3-[(2-hydroxyethoxy)methyl]imidazo[4,5-d] [1,3]diazepin-8-ol and some selected C-5 homologues of pentostatin

The synthesis of several analogues of (8R)-3-(2-deoxy-beta-D-erythro- pentofuranosyl)-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol (pentostatin, 1a) is described. Ring closure of 2-amino-1-(5-amino-1H-imidazol-4-yl)ethanone dihydrochloride (3) with triethyl orthoacetate or triethyl orthopropionate gave the C-5 methyl and ethyl ketoaglycons, 6,7-dihydro-5-methylimidazo[4,5-d][1,3]diazepin-8(3H)-one (4b) and 5-ethyl-6,7-dihydroimidazo[4,5-d][1,3]diazepin-8(3H)-one (4c), respectively. Stannic chloride catalyzed condensation of the pertrimethylsilyl derivatives of 4b and 4c with a protected glycosyl halide afforded anomeric mixtures of ketonucleosides 3-(2-deoxy-3,5-di-O-p-toluoyl-beta- and -alpha-D-erythro-pentofuranosyl)-6,7-dihydro-5-methylimidazo[4,5-d] [1,3]diazepin-8(3H)-one (5b and 6b) and 3-(2-deoxy-3,5-di-O-p-toluoyl)-beta- and -alpha-D-erythro-pentofuranosyl)-5-ethyl-6,7-dihydroimidazo[4,5-d]- [1,3]diazepin-8(3H)-one (5c and 6c), respectively. Subsequent separation of the anomers, followed by deprotection and reduction of 5b, 6b, and 5c, afforded the respective 8R and 8S isomers. Stannic chloride catalyzed condensation of pertrimethylsilyl ketoaglycon 4a with 2-(chloromethoxy)-1-(p-toluoyloxy) ethane to give ketonucleoside 6,7-dihydro-3-[[2-(p-toluoyloxy)ethoxy] methyl]imidazo[4,5-d][1,3]diazepin-8(3H)-one (9a) was followed by deprotection to 6,7-dihydro-3[(2-hydroxyethoxy)methyl]imidazo[4,5-d][1,3] diazepin-8(3H)-one (9b) and then reduction to the racemic acyclic pentostatin analogue (+/-)-3,6,7,8-tetrahydro-3-[ (2-hydroxyethoxy)methyl]imidazo[4,5-d][1,3]diazepin-8-ol (2). Ki values for the in vitro adenosine deaminase (EC 3.5.4.4; type I; calf intestinal mucosa) inhibitory activities of 1b, 1c, and 2 were determined to be 1.6 X 10(-8), 1.5 X 10(-6), and 9.8 X 10(-8) M, respectively. When compounds 2 and 9b were tested in combination with vidarabine against herpes simplex virus, type 1, in an HEp-2 plaque reduction assay, only compound 2 was able to potentiate the antiviral activity of vidarabine.     

Synthesis,antiviral and cytotoxic activity of 6-bromo-2,3-disubstituted-4(3H)-quinazolinones

In the present study, a series of 6-bromo-2,3-disubstitued-4(3H)-quinazolinones was synthesized by condensation of 6-bromo-2-substituted-benzoxazin-4-one with trimethoprim, pyrimethamine and lamotrigine. The chemical structures of the synthesized compounds were confirmed by means of IR, (1)H-NMR and mass spectral and elemental analysis. The antiviral activity and cytotoxicity of the compounds were tested in E(6)SM (Herpes simplex-1 KOS, Herpes simplex-1 TK-KOS ACV, Herpes simplex-2 G, Vaccinia virus, Vesicular stomatitis virus, Parainfluenza-3 virus, Reovirus-1, Sindbis virus, Coxsackie virus B4 and Punta Toro virus) and HeLa cell culture (Vesicular stomatitis virus, Coxsackie virus B4 and Respiratory syncyticla virus). Investigation of anti-HIV activity was done against replication of HIV-1 (HTLV-III B LAI) in MT-4 cells. 6-Bromo-2-phenyl-3-[(4-amino-5-(4-chlorophenyl)-6-ethylpyrimidin-2-yl]-4(3H)-quinazolinone (4) exhibited the most potent antiviral activity with a MIC of 1.92 microg/ml against vaccinia virus in E(6)SM cell culture. The other compounds did not exhibit antiviral activity nor afford significant cytoprotection to the E(6)SM and HeLa cell culture when challenged with the viruses. The study implies that 4 may possess activity against Pox viruses including variola. In the anti-HIV study, 6-bromo-2-methyl-3-[(4-amino-5-(4-chlorophenyl)-6-ethylpyrimidin-2-yl]-4(3H)-quinazolinone (3) and 6-bromo-2-phenyl-3-[(4-amino-5-(4-chlorophenyl)-6-ethylpyrimidin-2-yl]-4(3H)-quinazolinone (4) exhibited the least cytotoxic concentration (0.424, 0.461 microg/ml) which is an index of the infective viability of mock infected MT-4 cells with HIV-1. None of the compounds exhibited significant anti-HIV activity.     

Synthesis and in vitro biological activity of new deaza analogues of folic acid, aminopterin, and methotrexate with an L-ornithine side chain

The 5-deaza and 5,8-dideaza analogues of N alpha-pteroyl-L-ornithine (Pter-Orn), the 5-deaza, 8-deaza, and 5,8-dideaza analogues of N alpha-(4-amino-4-deoxypteroyl)-L-ornithine (APA-Orn), and the N delta-carboxymethyl derivative of N alpha-(4-amino-4-deoxy-N10-methylpteroyl)-L-ornithine (mAPA-Orn) were synthesized and tested as inhibitors of dihydrofolate reductase (DHFR) and as inhibitors of tumor cell growth in culture. Reductive amination of 2-acetamido-6-formylpyrido[2,3-d]pyrimidine-4(3H)-one with methyl N alpha-(4-aminobenzoyl)-N delta-(benzyloxycarbonyl)-L-ornithinate followed by removal of the blocking groups afforded the 5-deaza analogue of Pter-Orn, whereas N-alkylation of methyl N alpha-(4-aminobenzoyl)-N delta-(benzyloxycarbonyl)-L-ornithinate with 2-amino-6-(bromomethyl)quinazolin-4(3H)-one and deprotection gave the corresponding 5,8-dideaza analogue. Reductive coupling of 2,4-diaminopyrido[2,3-d]pyrimidine-6-carbonitrile and 4-aminobenzoic acid followed by reaction with 95-97% formic acid yielded 4-amino-4-deoxy-5-deaza-N10-formylpteroic acid, which on condensation with methyl N delta-(benzyloxycarbonyl)-L-ornithinate and deprotection gave the 5-deaza analogue of APA-Orn. A similar sequence starting from 2,4-diamino-quinazoline-6-carbonitrile led to the corresponding 5,8-dideaza compound, whereas treatment of 2,4-diamino-pyrido[3,2-d]pyrimidine-6-methanol with phosphorus tribromide followed by condensation with methyl N alpha-(4-aminobenzoyl)-N delta-(benzyloxycarbonyl)-L-ornithinate and deprotection afforded the 8-deaza analogue. For the preparation of the N delta-carboxymethyl derivative of mAPA-Orn, N alpha-(benzyloxycarbonyl)-L-ornithine was subjected to N delta-monoalkylation with glyoxylic acid and sodium cyanoborohydride, followed by N delta-acylation with ethyl trifluoroacetate, N alpha-deprotection by hydrogenolysis, condensation with 4-amino-4-deoxy-N10-methylpteroic acid, and N delta-deprotection by gentle treatment with ammonia. The 2,4-diamino derivatives all inhibited the growth of tumor cells in culture, with IC50 values of 0.2-2 microM, and inhibited purified DHFR with IC50 values of 0.02-0.08 microM. Deletion of ring nitrogens and N delta-carboxymethylation both increased potency in the cell growth assay; however, the ornithine derivatives were less potent than aminopterin or methotrexate.     

Characterization of the reaction products of 2'-deoxyguanosine and 1,2,3,4-diepoxybutane after acid hydrolysis: formation of novel guanine and pyrimidine adducts

1,2,3,4-diepoxybutane (DEB), an important in vivo metabolite of 1,3-butadiene (BD), is a potent mutagen and a known carcinogen. Recently, DEB has been shown to react with 2'-deoxyguanosine (dG) at 37 degrees C and pH 7.4 to yield a series of nucleoside adducts, resulting from alkylation at the 7-, 1-, and N(2)-positions of dG. In addition, adducts with fused ring systems are formed. In the present study, new adducts are characterized after DEB was allowed to react with dG at pH 7.4 and the reaction mixture was then subjected to acid hydrolysis. These adducts are 7-hydroxy-6-hydroxymethyl-5,6,7,8-tetrahydropyrimido[1,2-a]purin-10(1H)one (H2), 2-amino-1-(4-chloro-2,3-dihydroxybutyl)-1,7-dihydro-6H-purin-6-one (H4), 2-amino-1-(2,3,4-trihydroxybutyl)-1,7-dihydro-6H-purin-6-one (H1'/H5'), 7,8-dihydroxy-1,5,6,7,8,9-hexahydro-1,3-diazepino[1,2-a]purin-11(11H)one (H2'), and 5-(3,4-dihydroxy-1-pyrrolidinyl)-2,6-diamino-4(3H)pyrimidinone (H3'). The previously characterized guanine adducts, 2-amino-7-(3-chloro-2,4-dihydroxybutyl)-1,7-dihydro-6H-purin-6-one (H3) and 2-amino-7-(2,3,4-trihydroxybutyl)-1,7-dihydro-6H-purin-6-one (H4'), were also detected. Acid hydrolysis of purified dG-DEB adducts confirmed that H2, H3/H4', H2', and H4/H1'/H5' are the hydrolysis products of N-(2-hydroxy-1-oxiranylethyl)-2'-deoxyguanosine (P4-1 and P4-2), 6-oxo-2-amino-9-(2-deoxy-beta-d-erythro-pentofuranosyl)-7-(2-hydroxy-2-oxiranylethyl)-6,9-dihydro-1H-purinium ion (P5 and P5'), 7,8-dihydroxy-3-(2-deoxy-beta-d-erythro-pentofuranosyl)-3,5,6,7,8,9-hexahydro-1,3-diazepino[1,2-a]purin-11(11H)one (P6), and 1-(2-hydroxy-2-oxiranylethyl)-2'-deoxyguanosine (P8 and P9), respectively. On the other hand, the novel pyrimidine adduct H3' is formed by the decomposition of P5 and P5' during the incubation and hydrolysis. These results may facilitate the development of useful biomarkers of exposure to DEB and its precursor BD.     

Synthesis of 2-[1,2-dihydropyrazol-4-yl]-1,3,4-thiadiazole derivatives as potential antimicrobial agents

The synthesis of some 2-[1,2-dihydropyrazol-4-yl]-1,3,4-thiadiazole derivatives is performed by reacting 4-dithiocarboxylic acid hydrazides of 3-amino-1,2-dihydro-5H-pyrazol-5-one and 3-amino-1,2-dihydro-1-methyl-5H-pyrazol-5-one with carboxylic acid derivatives. The unusual behaviour of 3-amino-1,2-dihydro-1-methyl-5H-pyrazol-5-one towards acetylating agents is described. The antimicrobial activity of some 2-[1,2-dihydropyrazol-4-yl]-1,3,4-thiadiazole derivatives is tested in a preliminary screening.     

Synthesis of aminoalkaloids derived from 8-hydroxy-7-methoxy-2H-1-benzopyran-2-one with expected beta-adrenolytic action

Synthesis of 8-hydroxy-7-methoxy-2H-1-benzopyran-2-one and syntheses of several 8-(3-amino-2-hydroxypropoxy)-7-methoxy-2H-1-benzopyran-2-one derivatives with antiarrhythmic activity is described.     

Photolysis of 3-methyl- and 3-phenyl-4-amino-2-methyl-1-phenyl-3-pyrazolin-5-one (author's transl)

Photolysis of 3-Methyl- and 3-Phenyl-4-amino-2-methyl-phenyl-3-pyrazolin-5-one During the irradiation of aqueous solutions of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one ( 1d ) besides the compounds 2 and 3 characteristic photolysis products of pyrazolones (Type I), the compound 12 is obtained, which was formed from two molecules of 1d . 4-Amino-2-methyl-1,3-diphenyl-3-pyrazolin-5-one, however isomerises to 8, which upon further irradiation fragments into several components two of them being N-phenyloxamide and N,N′-diphenyloxamide.     

β-Lactame und β-Lactam-Zwischenprodukte, 2. Mitt.: Stereoselektive Synthese von cis-3-Amino-1,4-diphenyl-azetidin-2-on

β-Lactams and β-Lactam-Intermediates, II: Stereoselective Synthesis of cis-3-Amino-1,4-diphenyl-azetidin-2-one Phthalylglycyl chloride ( 1 ) reacts with benzalaniline ( 3 ) in the presence of triethylamine to yield 1,4-diphenyl-3-phthalimido-azetidin-2-one ( 5 ). The selectivity of formation of cis-β-lactam 5 was improved considerably by decreasing the concentration of chloride in the reaction-solution and by lowering of the temperature. Hydrazinolysis of 5 yields 3-amino-1,4-diphenyl-azetidin-2-one ( 8 ).     

Guanosine analogues. Synthesis of nucleosides of certain 3-substituted 6-aminopyrazolo[3,4-d]pyrimidin-4(5H)-ones as potential immunotherapeutic agents

Several guanosine analogues were synthesized in the pyrazolo[3,4-d]pyrimidine ring system with various substituents at the 3-position. The new analogues prepared here include the CH3 (2-amino-3-methyl-1-beta-D-ribofuranosylpyrazolo[3,4-d]pyrimidin-4 (5H)-one, 13a), the phenyl (2-amino-3-phenyl-1-beta-D-ribofuranosylpyrazolo[3,4-d]pyrimidin-4 (5H)-one, 13b), and the NH2 (3,6-diamino-1-beta-D-ribofuranosylpyrazolo[3,4-d]pyrimidin-4(5H)- one, 17) substituted derivatives. These new agents, as well as several other 3-substituted derivatives including H, Br, OCH3, COOH, and oxo, were evaluated for their ability to potentiate certain murine immune functions relative to the known active agent 5-amino-3-beta-D-ribofuranosylthiazolo[4,5-d]pyrimidine-2,7(3H,6H) -dione (4, 7-thia-8-oxoguanosine). The biological evaluation included the (1) ex vivo determination of increased natural killer cell function and (2) in vivo antiviral protection against a lethal challenge of Semliki Forest virus. The 3-unsubstituted (5a) and the 3-bromo (5c) derivatives were found to be the most active immunopotentiators in this series.     

Nucleosides of 1,4-thiazin-3-one and derivatives as tetrahedral intermediate analogues of enzymes in pyrimidine nucleoside metabolism

Reaction of the trimethylsilylated derivative of 1,4-thiazin-3-one with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose in the presence of SnCl4 gave, after deblocking, 4-beta-ribofuranosyl-1,4-thiazin-3-one (8). Treatment of 1,4-thiazin-3-one with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-alpha-D-erythro-pentofuranose in the presence of sodium hydride provided, after deblocking, the corresponding 2-deoxy-beta-D-ribofuranosyl derivatives (19). Oxidation of 4-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,4-thiazin-3-one (7) with 1 equiv of m-chloroperbenzoic acid resulted in 4-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,4-thiazine-2,3-dione (9) and 4-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,4-thiazin-3-one 1-oxide (10). Evidence is presented that indicates that the oxidation of the thiazine at the 2-position is due to a Pummerere rearrangement. The new compounds failed to show significant activity against tumor cell lines in culture, L1210 cells in vivo, virus cytotoxicity in cell culture, or cytidine deaminase.     

Comparison of in vitro and ex vivo antiplatelet effects of 1,2-benzisothiazolin-3-one and its 2-amino derivative

The in vitro and ex vivo antiplatelet effects of 2-amino-1,2-benzisothiazolin-3-one (1) are compared with those of its parent compound 1,2-benzisothiazolin-3-one (2) and with acetylsalicylic acid (ASA) against different agonists. 2-Amino-1,2-benzisothiazolin-3-one inhibits adenosine diphosphate (ADP)-, arachidonic acid (AA)- and collagen-induced human platelet aggregation in vitro, with IC50 values of 8.90 x 10(-5), 1.50 x 10(-6) and 5.11 x 10(-8) mol/l, respectively. The strong inhibitory activity is significant not only for collagen but also for AA-induced aggregation. The same compound inhibits ex vivo collagen- and particularly AA-induced rabbit platelet aggregation at the tested dose of 10 mg/kg i.m. In view of the potential use of 2-amino-1,2-benzisothiazolin-3-one as antithrombotic agent, the log P values for both 1,2-benzisothiazolin-3-one derivatives 1 and 2 are determined, to gain an understanding of the significance of the 2-amino group in the 1,2-benzisothiazolin-3-one moiety with respect to the biological activity under study.     

Kondensationen mit Hydrazin-N,N′-dicarbonsäurediamidin, 21. Mitt. β-Ketocarbonsäureester als Reaktionspartner

Condensations with 1,2-Hydrazinedicarboxamidine, XXI: β-Ketocarboxylic Esters as Reactants In preceding investigations it was assumed that the guanidinoaminopyrimidine structure is a common intermediate in the formation of hydrazo- and the triazolopyrimidines from 1,2-hydrazinedicarboxamidine (1) . This postulate is now supported by the isolation of 2-guanidinoamino-6-methyl-1,4-dihydropyrimidin-4-one (3) formed by the reaction of 1 with ethyl acetoacetate (2) and by the conversion of 3 into 2-amino-7-methyl-5,8-dihydro-s-triazolo[1,5-a]pyrimidin-5-one (8a) . In the course of this conversion 6,6′-dimethyl-2,2′hydrazo-1,4-dihydropyrimidin-4-one (4) is formed from 3 .     

Synthesis and anti-inflammatory evaluation of new substituted 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole derivatives

A series of heterocyclic derivatives including 1,2,4-triazole-3(4H)-one (3a,b), 1H-pyrazol-5(4H)-one (4,5), 1H-pyrazol-4-carbonitrile (7), pyridine-3-carbonitrile (8, 9a,b), pyrimidine-5-carbonitrile (10a,b), methylpyrimidin-2(1H)-one or thione (11a,b), pyrimidine-5-carboxylate (12a,b), quinazolin-5(6H)-one (13a,b) and indeno [1,2-d] pyrimidin-5-one (14a,b) moieties conjugated with 1,3-disubstituted pyrazole moiety were synthesized on reaction with semicarbazide, thiosemicarbazide, 3-amino-5-oxo-2-pyrazoline, cyanoacetohydrazide, 2-acetyl thiophene, p-chloroacetophenone, urea, thiourea and 1,3-dicarbonyl compounds, respectively, by using 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carboxaldehyde (2) as starting material. The structures of all the newly synthesized products have been established on the basis of analytical and spectral data. The anti-inflammatory screening showed that most of the obtained compounds were found to have significant anti-inflammatory activities with prostaglandin inhibition at a dose level of 2.5 and 5 mg/kg comparable to celecoxib as a reference control. The ulcer indices of all compounds are mainly in the safe level (UI = 2.10-4.27) except for compounds 9a and 14a, which were highly ulcerogenic.     

Synthesis,analgesic and anti-inflammatory activities of some novel 2,3-disubstituted quinazolin-4(3H)-ones

A series of novel 2-benzylamino-3-substituted quinazolin-4(3H)-ones have been synthesized by treating 3-amino-2-benzylamino quinazolin-4(3H)-one, with different aldehydes and ketones. The starting material 3-amino-2-benzylamino quinazolin-4(3H)-one was synthesized by nucleophilic substitution of thiomethyl group of 3-amino-2-methylthio quinazolin-4(3H)-one by benzylamine. The title compounds were investigated for analgesic and anti-inflammatory activities. All the test compounds exhibited significant analgesic activity, whereas the compound III is equipotent with diclofenac sodium. The compounds I, II and III showed more potent anti-inflammatory activity than diclofenac sodium.     

Synthesis, antibacterial, antifungal and anti-HIV evaluation of Schiff and Mannich bases of isatin derivatives with 3-amino-2-methylmercapto quinazolin-4(3H)-one

Isatin (Indole 2,3-dione), its 5-chloro and 5-bromo derivatives were added to 3-amino-2-methylmercapto quinazolin-4(3H)-one to form Schiff bases and the N-Mannich bases of these compounds were synthesized by reacting with formaldehyde and several secondary amines. Their chemical structures have been confirmed by means of their IR, 1H-NMR data and by elemental analysis. Investigation of antimicrobial activity of compounds was done by an agar dilution method against 26 pathogenic bacteria, 8 pathogenic fungi and anti-HIV activity against replication of HIV-1 (III B) in MT-4 cells. Among the compounds tested 5-chloro-3-(3',4'-dihydro-2'-methylmercapto-4'-oxoquinazolin-3'-yl )- l-morpholino methyl imino isatin was the most active antimicrobial agent.     

Phenoxazine derivatives inactivate human cytomegalovirus, herpes simplex virus-1, and herpes simplex virus-2 in vitro.

We examined whether phenoxazine derivatives, 2-amino-4,4alpha-dihydro-4alpha-7-dimethyl-3H-phenoxazine-3-one (Phx-1), 3-amino-1,4alpha-dihydro-4alpha-8-dimethyl-2H-phenoxazine-2-one (Phx-2), and 2-amino-phenoxazine-3-one (Phx-3) may have antiviral activity against herpes family viruses: human cytomegalovirus (HCMV), herpes simplex virus type 1 (HSV-1), and herpes simplex virus type 2 (HSV-2). The antiviral activity was evaluated by the selectivity index (SI), which is the ratio of 50% cytotoxic concentration (CC(50)) and 50% antiviral concentration (IC(50)). Among these phenoxazines, Phx-2 exerted strong antiviral activity to HCMV with the SI of 200, while Phx-1 and Phx-3 exerted no marked anti-HCMV activity. Phx-2 also showed moderate inhibition of HSV-1 and HSV-2, with the SI of 6.7 and 17, respectively. In the time-of-addition experiments, inhibitory effect of Phx-2 against HCMV was active even when applied to cells at 100 h after HCMV infection, while ganciclovir (GCV) showed potent inhibition when applied to cells before 42-h post-infection, but its inhibitory effects disappeared thereafter. Attachment and penetration of HCMV was not affected by the presence of Phx-2. When HCMV was pretreated with Phx-2, concentration-dependent virucidal action was observed, suggesting that Phx-2 inactivates HCMV directly. From these data, it was found that Phx-2 might have a different anti-HCMV target from GCV.