Shivaji S. Pawar

Synthesis and anti-inflammatory activity of some new 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazole derivatives

A series of 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazoles were designed and synthesized in order to obtain new compounds with potential anti-inflammatory activity. The title compounds were screened for in vivo anti-inflammatory activity by using Carrageenan induced rat paw edema method. Diclofenac sodium was used as a standard drug for comparison. Out of the 30 compounds tested, compound 19a, 19b, 25a, 25b exhibited significant anti-inflammatory activity. Selected compounds were also screened for in vitro COX-2 inhibition assay and analgesic activity in the acetic acid induced writhing model.

Alum (KAl(SO4)2·12H2O)-Catalyzed, Eco-Friendly, and Efficient One-Pot Synthesis of 2-Arylbenzothiazoles and 2-Arylbenzoxazole in Aqueous Medium

Alum (KAl(SO4)2·12H2O) performs as a novel catalyst for the synthesis of 2-arylbenzothiazoles and 2-arylbenzoxazole from o-aminothiophenol and o-aminophenol with various substituted aldehydes in good to excellent isolated yields (85–95%) using water as a solvent at ambient temperature. Several solvents were examined for this reaction; however, in terms of reaction yield and time, water was found to be the optimum solvent. The remarkable advantages offered by this method are an inexpensive and easily available catalyst, a simple procedure, mild conditions, much faster (60–90 min) reactions, and good to excellent yields of products.

Synthesis of novel bioactive derivatives of 3-(4-chlorophenyl)-2-hydrazino-5,6,7,8-tetrahydrobenzo(b)thieno[2,3-d]pyrimidine-4(3H)-ones.

A series of triazolo[4,3-a]tetrahydrobenzo(b)thieno[3,2-e]pyrimidine-5(4H)-ones (12a-n) were synthesized and evaluated for CNS depressant, skeletal muscle relaxant and anticonvulsant activities by photoactometer, Rotarod and pentylenetetrazole induced the convulsions method respectively in Swiss albino mice. Diazepam was used as standard drug. The five derivatives 12b, 12c, 12d, 12i and 12m showed the CNS depressant and skeletal muscle relaxant activities comparable to those of diazepam at a dose of 5mg/kg. These derivatives also exhibited good activity when tested for anticonvulsant activity in mice at different dose levels. The ED(50) values for these derivatives are in the range of 4.40-9.33 mg/kg.

Synthesis and pharmacological investigation of novel 2-substituted-3-carboxamido-4H-pyrimidobenzothiazole derivatives as a new class of H1-antihistaminic agent

With the aim of developing potential H1-antihistaminic agents, a series of novel 2-substituted-3-carboxamido-4-oxo-4H-pyrimido[2,1-b][1,3]benzothiazole (8a–g) and 2-substituted-3-carboxamido-8-chloro-4-oxo-4H-pyrimido[2,1-b][1,3]benzothiazole (9a–g) were synthesized and evaluated in vitro for H1-antihistaminic activity on guinea pig ileum preparation. IC50 values of the compounds were found to be in the micromolar range. Chlorpheniramine maleate was used as a standard drug. The active derivatives (8d–8g and 9d–9g) were found to have IC50 values comparable to reference standard chlorpheniramine maleate. The sedative potential of both series (8a–g and 9a–g) is less than the reference drug. Hence, it could serve as prototype molecules for further development as a new class of H1-antihistaminic agents.

SONICATED ASSISTED SYNTHESIS OF BENZIMIDAZOLES, BENZOXAZOLES AND BENZOTHIAZOLES IN AQUEOUS MEDIA

ABSTRACT Ammonium nickel sulphate [(NH 4 ) 2 SO 4 .NiSO 4 .6H 2 O] was found as a new catalyst to synthesis 2-aryl benzimidazole, 2-aryl benzothiazole and 2-aryl benzoxazole in aqueous media under sonication irradiation. The procedure is an eco-friendly, efficient and provides simple workup and good yield. Keywords : - Benzimidazole, benzothiazole, benzoxazole, aqueous media, sonication, ammonium nickel sulphate. e-mail: snthore@rediffmail.com INTRODUCTION The benzimidazoles, benzoxazole and benzthaizoles are an important heterocyclic nucleus which has been widely used in medicinal chemistry 1,2 . These heterocycles are an important pharmacophore 3,4 in drug discovery and good intermediate 5 in synthesis of many important organic compounds. These heterocycles shows different pharmacological properties such as antibacterial 6 , antiviral 7 , antifugal 8 , anticancer 9 , anticonvulsant 10 and immunosuppressant 11 .These heterocycles can be prepared by condensing carboxylic acid 12 , acid chloride