Synthesis and pharmacological activities of novel 3-(isoxazol-3-yl)-quinazolin-4(3H)-one derivatives

Several new 3-(isoxazol-3-yl)-quinazolin-4(3H)-one derivatives were synthesized and tested for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effect. A few compounds were as active as phenylbutazone in the writhing and acetic acid peritonitis tests. They had a very low ulcerogenic effect.     

Researches on antiinflammatory agents. Studies on some 1-methyl- or 1-phenyl-6-(2-substitutedphenyl)-pyrazolo[3,4-d]-1,3-oxazin-4(1H)-ones.

Following our research on analgesic and antiinflammatory active compounds containing the pyrazole nucleus, a number of new 1-methyl- or 1-phenyl-6-(2-substitutedphenyl)-pyrazolo[3,4-d]-1,3-oxazin- 4(1H)-ones was synthesized and tested, together with a few analogues previously obtained, for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effects. One of the tested compounds showed activity comparable to that of phenylbutazone and, at the same time, higher LD50 and a very low ulceration index.     

Synthesis and evaluation of the analgesic and anti-inflammatory activity of new 3(2H)-pyridazinone derivatives

A series of 6-substituted-3(2H)-pyridazinone derivatives were synthesized and evaluated for analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. Analgesic and anti-inflammatory activities of the title compounds have been evaluated. Four of the ten tested compounds possessed significant analgesic effects in the phenylbenzoquinone-induced writhing test (PBQ test). The most active derivatives 8a, 8b, 8d, 8e were void of gastric ulcerogenic effect or acute toxicity at the maximal dose (200 mg/kg p.o.). In the carrageenan-induced paw edema model, compound 8d (6- [4- (2-fluorophenyl) piperazin-1-yl]-3(2H)-pyridazinone) showed anti-inflammatory activity similar to that of the standard drug indometacin (CAS 53-86-1). A significant dependence of the anti-inflammatory effect on the substituents was observed; The pharmacological study of these compounds confirms that modification of the chemical group at position 6 of the 3(2H)-pyridazinone ring influences analgesic and anti-inflammatory activities.     

Synthesis and biological evaluation of some hydroxypyrazole derivatives as anti-inflammatory-antimicrobial agents

Some hydroxypyrazole derivatives 2-7 were synthesized by cyclocondensation of the keto-ester 1 with hydrazines hydrate or substituted hydrazines followed by reduction and acylation with acetic anhydride or trifluoroacetic anhydride. The newly synthesized compounds were evaluated for their anti-inflammatory, antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compounds N-(4-(5-hydroxy-1-trifluoroacetyl-1H-pyrazol-3-yl)phenyl) trifluoroacetamide 4b, 3-(4-nitrophenyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-ol 5b, and N-(4-(5-hydroxy-1-methyl-1H-pyrazol-3-yl)phenyl)trifluoroacetamide 7b were proved to be the most active anti-inflammatory, antimicrobial agents in the present study with a good safety margin and minimal or no ulcerogenic effect.     

Synthesis and pharmacological activity of imidazolyn-5-ones

A new series of imidazolyn-5-one derivatives were synthesized. These compounds were screened for their analgesic, anti-inflammatory and antipyretic activities, as well as for their ulcerogenic potential, for behavioural effects and acute toxicity. Some of them showed higher analgesic activity than phenylbutazone (PBZ), but lower anti-inflammatory activity. Their ulcerogenic effect was lesser than that of the reference drug.     

Novel pyrazole derivatives as potential promising anti-inflammatory antimicrobial agents

Four series of 1H-pyrazole derivatives have been synthesized. The first series was synthesized starting by condensing the hydrazine derivatives 1a-d with 4-(1-ethoxycarbonyl-2-oxopropyl)azobenzoic acid 2a in ethanol or glacial acetic acid to generate the corresponding pyrazoline derivatives 3a-d. Likewise, heating 1a-d with 4-(1-acetyl-2-oxopropyl)azobenzoic acid 2b gave rise to the pyrazole derivatives 4a-d. Similarly, reaction of 1a-d with ethyl 2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylazo)-3-oxobutanoate 2c or 3-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl azo)pentane-2,4-dione 2d in ethanol or glacial acetic acid led to the corresponding pyrazoline derivatives 5a-d or pyrazole derivatives 6a-d. The newly synthesized compounds were evaluated for their anti-inflammatory-antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compound 6c, proved to be the most active anti-inflammatory-antimicrobial agent in the present study with a good safety margin and no ulcerogenic effect.     

Design and synthesis of some substituted 1H-pyrazolyl-oxazolidines or 1H-pyrazolyl-thiazolidines as anti-inflammatory-antimicrobial agents

Four series of 1 H-pyrazole derivatives have been synthesized. The first series was synthesized starting with the reaction of 3-(5-bromo-2-thienyl)-1-phenyl-1 H-pyrazole-4-carboxaldehyde 1 with L-serine, L-cysteine, or L-penicillamine, followed by N-protection using (Boc)(2)O to provide compounds 2. The latter compounds could be N-deprotected by 4N HCl/dioxane to afford the second series 3 or reacted with NH(4)OH in the presence of DCC/HOBt to give the corresponding amides 4 followed by N-deprotection giving rise to compounds 5. The newly synthesized compounds were evaluated for their anti-inflammatory-antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compound 5b (2RS, 4R)-2-[3-(5-bromo-2-thienyl)-1-phenyl-1H-pyrazol-4-yl]-5-methylthiazolidine-4-carboxamide, proved to be the most active anti-inflammatory-antimicrobial agent in the present study with a good safety margin and no ulcerogenic effect.     

Synthesis and pharmacological evaluation of novel quinoxalines as potential nonulcerogenic anti-inflammatory and analgesic agents

Some new substituted quinoxaline and furo[2,3-b]quinoxaline derivatives have been synthesized and tested for their anti-inflammatory and analgesic activities and for their ulcerogenic potential. The pharmacological evaluation of selected synthesized compounds revealed that 5a was equipotent and compounds 3, 4b, 4e and 5b possessed strong anti-inflammatory activity in chronic inflammatory models compared with indometacin (CAS 53-86-1) as reference drug. In addition, compound 4a was the safest one and the others showed little ulcerogenic activity. All the tested compounds showed moderate analgesic activity compared to the reference drug.     

Synthesis of 3-(2-pyridylethyl)benzoxazolinone derivatives: potent analgesic and antiinflammatory compounds inhibiting prostaglandin E2.

Fourteen new 3-[2-(2- and/or 4-pyridyl)ethyl]benzoxazolinone derivatives have been synthesized by reacting 2- and/or 4-vinylpyridine and appropriate benzoxazolinones. Their chemical structures have been proven by IR, 1H-NMR, and elemental analysis. Analgesic activities of these compounds were investigated by a "Modified Koster's Test". Except for compounds 10 and 11, all the new derivatives showed higher analgesic activities than aspirin. Therefore the compounds were screened for their antiinflammatory activities using the carrageenan hind paw edema test. The compounds (6, 7, 8, 9, 14, and 17) that showed high antiinflammatory activity were then further screened for their ability to inhibit prostaglandin E2 (PGE2) induced paw edema. Although all the benzoxazolinone derivatives synthesized in this study showed higher antiinflammatory activity compared to indomethacin, those without a substituent at the 6-position of the ring were significantly more active than the rest of the group, and their ulcerogenic activities and ED50 values indicate them as promising derivatives for further study.     

Synthesis and evaluation of the analgesic and antiinflammatory activities of N-substituted salicylamides

Some N-heterocyclic salicylamide derivatives were prepared by fusion of phenyl salicylate and heterocyclic amines, whereas other ones were synthesized by ring closure using N-salicyloyl-N'-anthranylhydrazine as starting material. All the compounds were tested for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effects, in order to ascertain if the N-substitution would offer any advantages. Some derivatives were more effective than salicylamide and ulcerogenic activity was variably lowered.     

Synthesis of novel 3-butyl-2-substituted amino-3H-quinazolin-4-ones as analgesic and anti-inflammatory agents

A variety of novel 3-butyl-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 3-butyl-2-hydrazino-3H-quinazolin-4-one with various aldehydes and ketones. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. The compound 3-butyl-2-(1-methylbutylidene-hydrazino)-3H-quinazolin-4-one (AS3) emerged as the most active analgesic agent. Compound 3-butyl-2-(1-ethylpropylidene-hydrazino)-3H-quinazolin-4-one (AS2) emerged as the most active anti-inflammatory agent and is moderately more potent when compared to the reference standard diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic potential when compared to aspirin.     

Non-carboxylic analogues of naproxen: design, synthesis, and pharmacological evaluation of some 1,3,4-oxadiazole/thiadiazole and 1,2,4-triazole derivatives

A series of substituted 1,3,4-oxadiazole (2-7 and 14-19), 1,2,4-triazole (20-25), and 1,3,4-thiadiazole (26-31) derivatives of naproxen have been synthesized by cyclization of 2-(6-methoxy-2-naphthyl)propanoic acid hydrazide 1 and N(1)[2-(6-methoxy-2-naphthyl) propanoyl]-N(4)-alkyl/aryl-thiosemicarbazides (8-13) under various reaction conditions. All the compounds were screened for their anti-inflammatory activity by carrageenan-induced rat paw edema test method. Compounds showing high anti-inflammatory activity were also tested for their analgesic, ulcerogenic, and lipid peroxidation. Few of the synthesized compounds showed significant anti-inflammatory and analgesic activities along with reduced ulcerogenic effect and lipid peroxidation.     

A study of anti-inflammatory activity of some novel alpha-amino naphthalene and beta-amino naphthalene derivatives

In the present study, some naphthalene derivatives have been synthesized by incorporating azetidinyl and thiazolidinyl moieties at its alpha- or beta-positions such as alpha-(3-chloro-2-oxo-4-substituted)aryl-1-azetidinyl)naphthalenes 6-10, alpha-((substituted)aryl-4-oxo-1,3-thiazolidin-3-yl)naphthalenes 11-15, beta-(3-chloro-2-oxo-4-substituted aryl-1-azetidinyl)naphthalenes 21-25, and beta-(substituted aryl-4-oxo-1,3-thiazolidin-3-yl)naphthalenes 26-30. These compounds have also been screened for acute toxicity and anti-inflammatory and analgesic activities. Compounds which showed better anti-inflammatory and analgesic activities were also examined for their ulcerogenic liability and underwent a cyclooxygenase assay. Two compounds, 12 and 28, were found to exhibit potent anti-inflammatory activity as compared to the standard drugs phenylbutazone and naproxen.     

A novel COX-2 inhibitor pyrazole derivative proven effective as an anti-inflammatory and analgesic drug

The introduction of new COX-2 inhibitors with high efficacy and enhanced safety profile would be a great achievement in the development of anti-inflammatory drugs. This study was designed to screen and assess the anti-inflammatory and analgesic activities as well as some of the expected side effects of some pyrazole derivatives, newly synthesized as potential COX-2 inhibitors at the Faculty of Pharmacy, Alexandria University and compared to indomethacin and celecoxib. Twelve compounds were screened for their anti-inflammatory activity using carrageenan-induced paw oedema and cotton pellet granuloma tests. On the basis of their apparent anti-inflammatory activity, four compounds with different substitutions were selected for the evaluation of their analgesic activity using the formalin-induced hyperalgesia and hot-plate tests. Compound AD 532, ((4-(3-(4-Methylphenyl)-4-cyano-1H-pyrazol-1-yl)benzenesulfonamide)), showed very promising results. In the single-dose and subchronic toxicity studies, compound AD 532 showed no ulcerogenic effect and produced minimal effects on renal function. Furthermore, compound AD 532 was a less potent inhibitor of COX-2 in vitro than celecoxib, which may indicate lower potential cardiovascular toxicity. It is concluded that compound AD 532 appears to be a promising and safe option for the management of chronic inflammatory conditions. This study recommends more in-depth investigation into the therapeutic effects and toxicity profile of this compound including its cardiovascular toxicity.     

Synthesis and pharmacological study of some 3-(isoxazol-5-yl)-quinazolin-4(3H)-ones.

A number of new 3-(isoxazol-5-yl)-quinazolin-4(3H)-ones was prepared and tested, together a few analogues previously obtained, for their analgesic, antipyretic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effects. In the carrageenan rat foot edema model one of the tested compounds showed activity and LD50 comparable to that of ASA, but the ulceration index approximated zero value.     

Synthesis and Pharmacological Investigation of 5-Substituted-3-methylsulfanyl-1H-pyrazole-4-carboxylic Acid Ethyl Esters as New Analgesic and Anti-inflammatory Agents

To synthesize a new series of 5-substituted-3-methylsulfanyl-1H-pyrazole-4-carboxylic acid ethyl esters for their analgesic and anti-inflammatory activity.The title compound synthesized by reacting the amino group of 5-amino-3-methylsulfanyl-1H-pyrazole-4-carboxylic acid ethyl ester with acid anhydrides, acid chlorides and phenyl dithiocarbamates. The synthesized compounds were characterized by IR, 1H-NMR and mass spectral data; the purity of the compounds was determined by elemental analysis. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic behaviour.The compound 5-benzoylamino-3-methylsulfanyl-1-phenyl-1H-pyrazole-4-carboxylic acid ethyl ester (4c) emerged as the most active compound and exhibiting imperative analgesic and anti-inflammatory activities. Interestingly the test compounds showed only mild ulcerogenic potential when compared to indomethacin.The compound (4c) could serve as a lead molecule for further modification to obtain a clinically useful novel class of analgesic and anti-inflammatory agents.     

Synthesis,analgesic and anti-inflammatory activities of new methyl-imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles

Background

Long-term clinical employment of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with significant side effects including gastrointestinal (GI) lesions and kidney toxicity. In this paper we designed and synthesized new imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles by molecular hybridization of previously described anti-inflammatory compounds in the hope of obtaining new safer analgesic and anti-inflammatory agents.

Methods

The target structures were synthesized by preparation of 5-methyl-1H-imidazole-4-carboxylic acid ethyl ester 5. The reaction of hydrazine hydrate with this ester afforded the 5-methyl-1H-imidazole-4-carboxylic acid hydrazide 6 which was converted to target compounds 7-15 according to the known procedures. In silico toxicity risk assessment and drug likeness predictions were done, in order to consider the privileges of the synthesized structures as drug candidates.

Results and discussion

The analgesic and anti-inflammatory profile of the synthesized compounds were evaluated by writhing and carrageenan induced rat paw edema tests respectively. Compounds 8, 9 and 11-13 and 15 were active analgesic agents and compounds 8, 9 and 11-13 showed significant anti-inflammatory response in comparison with control. Compounds 11 and 13 were screened for their ulcerogenic activities and none of them showed significant ulcerogenic activity. The active Compounds 11 and 12 showed the highest drug likeness and drug score.

Conclusions

The analgesic and anti-inflammatory activities of title compounds were comparable to that of standard drug indomethacin with a safer profile of activity. The results revealed that both of oxadiazole and triazole scaffolds can be determined as pharmacophores. The in silico predictions and pharmacological evaluations showed that compounds 11 and 12 can be chosen as lead for further investigations.     

Synthesis and pharmacological activity of 1,2,4-triazolo[4,3-a]quinolines

The synthesis of a series of 1,2,4-triazolo[4,3-a]quinoline derivatives is described; their structures were assigned by 1H NMR and analytical data. The new compounds were tested in vivo for their antiinflammatory and analgesic activities, as well as for their ulcerogenic action. Some of the tested triazoles showed an analgesic activity in the acetic acid writhing test and antiinflammatory properties on carrageenan paw edema assay.     

Chemical and pharmacological investigations on 2H-pyridazino[4,5-b] [1,4]benzothiazin-1(10H)-one derivatives

The methylation of 2H-pyridazino [4,5-b][1,4]benzothiazin-1(10H)-one-5,5-dioxide 2 and the oxidation of 2-methyl-2H-pyridazino[4,5-b][1,4]benzothiazin-1(10H)-one 3 produced the same compound 4. On the contrary, in the 2-dialkylaminoalkylic series, the dialkylamino-alkylation and the oxidation reactions, carried out on compounds 2 and 8 respectively, afforded derivatives 7 and 9. In addition, the behaviour to the oxidation of the corresponding 10-methyl and 10-dialkylaminoalkyl analogues is also described. The synthesized compounds were tested for their analgesic, antiexudative and anti-inflammatory activities. The pharmacological results showed that in general dialkylaminoalkyl derivatives are more active than methyl derivatives. In particular, compounds 7 b, 9 b and 11 c exhibited an analgesic activity comparable to that of phenylbutazone; moreover 10-substituted compounds 11 a, 11 b and 11 c, screened p.o. as anti-inflammatory agents in rats, resulted equipotent to phenylbutazone and more active than 2-substituted isomers. These activities are coupled with a high LD50 and a very low ulcerogenic potential.     

Synthesis and pharmacological investigation of novel 3-(3-methylphenyl)-2-substituted amino-3H-quinazolin-4-ones as analgesic and anti-inflammatory agents

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.