Dhanabal Kumarasamy

A series of 4-substituted 3,4-dihydropyrimidine-2-ones (DHPM) was synthesized, characterized by IR, 1H NMR, 13C NMR and HRMS spectra. The compounds were evaluated in vitro for their antiviral activity against a broad range of DNA and RNA viruses, along with assessment for potential cytotoxicity in diverse mammalian cell lines. Compound 4m, which possesses a long lipophilic side chain, was found to be a potent and selective inhibitor of Punta Toro virus, a member of the Bunyaviridae. For Rift… Show more

A series of 4-substituted 3,4-dihydropyrimidine-2-ones (DHPM) was synthesized, characterized by IR, 1H NMR, 13C NMR and HRMS spectra. The compounds were evaluated in vitro for their antiviral activity against a broad range of DNA and RNA viruses, along with assessment for potential cytotoxicity in diverse mammalian cell lines. Compound 4m, which possesses a long lipophilic side chain, was found to be a potent and selective inhibitor of Punta Toro virus, a member of the Bunyaviridae. For Rift Valley fever virus, which is another Bunyavirus, the activity of 4m was negligible. DHPMs with a C-4 aryl moiety bearing halogen substitution (4b, 4c and 4d) were found to be cytotoxic in MT4 cells. Show less

A new series of 3-(4-ethylphenyl)-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-(4-ethylphenyl)-3H-quinazolin-4-one from 4-ethyl aniline with a variety of aldehydes and ketones. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. The compound 2-(N′-3-pentylidene-hydrazino)-3-(4-ethylphenyl)-3H-quinazolin-4-one (AS2) emerged as the most active compound of the series and was moderately… Show more

A new series of 3-(4-ethylphenyl)-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-(4-ethylphenyl)-3H-quinazolin-4-one from 4-ethyl aniline with a variety of aldehydes and ketones. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. The compound 2-(N′-3-pentylidene-hydrazino)-3-(4-ethylphenyl)-3H-quinazolin-4-one (AS2) emerged as the most active compound of the series and was moderately more potent than the reference standard diclofenac sodium. Interestingly the test compounds showed only mild ulcerogenic potential when compared to aspirin. Show less

A series of novel 4-(4-ethylphenyl)-1-substituted-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones were synthesized by the cyclization of 2-hydrazino intermediate with various electrophile. The starting material 2-hydrazino compound was synthesized from 2-ethyl aniline by a new innovative route with improved yield. When tested for their in vivo H1-antihistaminic activity on conscious guinea pigs, all the test compounds significantly protected the animals from histamine induced bronchospasm. The… Show more

A series of novel 4-(4-ethylphenyl)-1-substituted-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones were synthesized by the cyclization of 2-hydrazino intermediate with various electrophile. The starting material 2-hydrazino compound was synthesized from 2-ethyl aniline by a new innovative route with improved yield. When tested for their in vivo H1-antihistaminic activity on conscious guinea pigs, all the test compounds significantly protected the animals from histamine induced bronchospasm. The compound II emerged as the most active compound of the series and it is more potent (73.93% protection) when compared to the reference standard, chlorpheniramine maleate (71% protection), it showed negligible sedation (10%) when compared to chlorpheniramine maleate (30%). Therefore compound II will serve as prototype molecule for further development as a new class of H1-antihistamines Show less

A variety of novel 3-(3-methylphenyl)-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-(3-methylphenyl)-3H-quinazolin-4-one with a variety of aldehydes and ketones. The starting material 2-hydrazino-3-(3-methylphenyl)-3H-quinazolin-4-one was synthesized from 3-methyl aniline. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. Compound… Show more

A variety of novel 3-(3-methylphenyl)-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-(3-methylphenyl)-3H-quinazolin-4-one with a variety of aldehydes and ketones. The starting material 2-hydrazino-3-(3-methylphenyl)-3H-quinazolin-4-one was synthesized from 3-methyl aniline. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. Compound 2-(1-ethylpropylidene-hydrazino)-3-(3-methylphenyl)-3H-quinazolin-4-one (AS2) was the most active analgesic agent. Compound 2-(1-methylbutylidene-hydrazino)-3-(3-methylphenyl)-3H-quinazolin-4-one (AS3) was the most active anti-inflammatory agent and was moderately more potent than the reference standard diclofenac sodium. The test compounds showed only mild ulcerogenic potential compared with aspirin. Show less

The title compounds 2-methyl-3-(substituted methylamino)-(3 H )-quinazolin-4-ones were synthesized by condensing the active hydrogen atom of the amino group of 3-amino-2-methyl-(3 H )-quinazolin-4-one with formaldehyde and appropriate amines. Their structures were confirmed by spectral data (IR, 1H-NMR and Mass) and the purity was ascertained by elemental analysis. Investigation of antimicrobial activity of the test compounds was performed by agar dilution method against 7 pathogenic bacteria… Show more

The title compounds 2-methyl-3-(substituted methylamino)-(3 H )-quinazolin-4-ones were synthesized by condensing the active hydrogen atom of the amino group of 3-amino-2-methyl-(3 H )-quinazolin-4-one with formaldehyde and appropriate amines. Their structures were confirmed by spectral data (IR, 1H-NMR and Mass) and the purity was ascertained by elemental analysis. Investigation of antimicrobial activity of the test compounds was performed by agar dilution method against 7 pathogenic bacteria, 3 pathogenic fungi and antiHIV activity against replication of HIV-1(IIIB) and HIV-2 (ROD) in MT-4 cells. The compounds exhibited significant antibacterial and antifungal activities. Show less

A variety of novel 3-phenyl-2-substituted-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-phenyl-3H-quinazolin-4-one with different aldehydes and ketones. The starting material 2-hydrazino-3-phenyl-3H-quinazolin-4-one was synthesized from aniline. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. While the test compounds exhibited significant activity, compounds… Show more

A variety of novel 3-phenyl-2-substituted-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-phenyl-3H-quinazolin-4-one with different aldehydes and ketones. The starting material 2-hydrazino-3-phenyl-3H-quinazolin-4-one was synthesized from aniline. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. While the test compounds exhibited significant activity, compounds, 2-(N′-2-butylidene-hydrazino)-3-phenyl-3H-quinazolin-4-one (AS1), 2-(N′-3-pentylidene-hydrazino)-3-phenyl-3H-quinazolin-4-one (AS2) and 2-(N′-2-pentylidene-hydrazino)-3-phenyl-3H-quinazolin-4-one (AS3), exhibited moderate analgesic activity. The compound 2-(N′-2-pentylidene-hydrazino)-3-phenyl-3H-quinazolin-4-one (AS3) showed more potent anti-inflammatory activity when compared to the reference standard diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic side effect when compared to aspirin. Show less

A variety of novel 2-methylthio-3-substituted-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones have been synthesized by reacting (2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)dithiocarbamic acid methyl ester (5) with a variety of amines. The starting material dithiocarbamate (5) was synthesized from 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thiophene (1) by a novel innovative route. The title compounds were investigated for analgesic… Show more

A variety of novel 2-methylthio-3-substituted-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-4(3H)-ones have been synthesized by reacting (2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)dithiocarbamic acid methyl ester (5) with a variety of amines. The starting material dithiocarbamate (5) was synthesized from 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzo (b) thiophene (1) by a novel innovative route. The title compounds were investigated for analgesic, anti-inflammatory, ulcerogenicity index and antibacterial activities. While the test compounds exhibited significant activity, the compounds 1-methyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A1), 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A2), 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A4) showed more potent analgesic activity and the compounds 1-dimethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d]pyrimidin-3-yl)thiourea (A2), 1-diethyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno-[2,3-d]pyrimidin-3-yl)thiourea (A3) and 1-pyrrolidinyl-3-(2-methylthio-4-oxo-3H-5,6,7,8-tetrahydrobenzo (b) thieno[2,3-d] pyrimidin-3-yl)thiourea (A4) showed more potent anti-inflammatory activity than the reference standard diclofenac sodium. Show less