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An improved method for the synthesis of some new dihydropyrimidines from aromatic aldehydes, 1,3-dicarbonyl compounds, and thiourea with significant enhancement in reaction rates, short reaction time (4–6 h), good to excellent yields (70–93%), and ambient temperature using molecular iodine as catalyst is described. The biological evaluation revealed that the newly synthesized compounds and exhibited good antimicrobial activity and moderate antimycobacterial activity against Mycobacterium tuberculosis H37RV.

Heterosubstituted chalcones and oxopyrimidines were synthesized by the reaction of 2-(4-Chlorophenyl)imidazo[1,2-a]pyridine-3-carbaldehyde 1 and different aryl acetophenone in the presence of catalytic amount of 40% alkali to give (2E)-3-(2-(4-chlorophenyl)imidazo[1,2-a]pyridin-3-yl)-1-arylprop-2-en-1-ones 2a–l. Compounds 2a–l on reaction with urea in the presence of basic catalyst such as KOH to give 6-(2-(4-chlorophenyl)imidazo[1,2-a]pyridin-3-yl)-4-aryl pyrimidin-2(1H)-ones 3a–l. Their IR, 1H-NMR, MASS spectral data, and elemental analysis were in accord with assigned structure. All the newly synthesized compounds were screened for their antimicrobial activity. J. Heterocyclic Chem., (2012).

The objective of the current study was the development of a simple, precise and accurate isocratic reversed-phase stability indicating Ultra Performance Liquid Chromatography [UPLC] assay method and validated for determination of ticlopidine hydrochloride in solid pharmaceutical dosage forms. Isocratic separation was achieved on a Zorbax SB-C18 (50 mm × 4.6 mm, 1.8 μm) column using mobile phase of methanol-0.01 M ammonium acetate buffer, pH 5.0 (80:20, v/v) at a flow rate of 0.8 ml min(-1), the injection volume was 4.0 μl and the detection was carried out at 235 nm by using photo-diode array detector. The drug was subjected to oxidation, hydrolysis, photolysis and heat to apply stress condition. The method was validated for specificity, linearity, precision, accuracy, robustness and solution stability. The method was linear in the drug concentration range of 62.5-375 μg ml(-1) with a correlation coefficient of 0.9999. The precision (relative standard deviation - RSD) of six samples was 1.31% for repeatability and the intermediate precision [RSD] among six-sample preparation was 0.77%. The accuracy (recovery) was between 98.80% and 101.50%. Degradation products produced as a result of stress studies did not interfere with detection of ticlopidine hydrochloride and the assay can thus be considered stability indicating.

The formation of dihydropyrimidines (IV) and (VII) from dicarbonyl compounds, aromatic aldehydes, and thiourea derivatives occurs with significant enhancement with regard to reaction rates, reaction time, and yield by using molecular iodine as the catalyst.

Heterosubstituted chalcones and oxopyrimidines were synthesized by the reaction of 2-(4-Chlorophenyl)imidazo[1,2-a]pyridine-3-carbaldehyde 1 and different aryl acetophenone in the presence of catalytic amount of 40% alkali to give (2E)-3-(2-(4-chlorophenyl)imidazo[1,2-a]pyridin-3-yl)-1-arylprop-2-en-1-ones 2a–l. Compounds 2a–l on reaction with urea in the presence of basic catalyst such as KOH to give 6-(2-(4-chlorophenyl)imidazo[1,2-a]pyridin-3-yl)-4-aryl pyrimidin-2(1H)-ones 3a–l. Their IR, 1H-NMR, MASS spectral data, and elemental analysis were in accord with assigned structure. All the newly synthesized compounds were screened for their antimicrobial activity. J. Heterocyclic Chem., (2012).

All newly synthesized compounds are tested for their antibacterial and antitubercular activity.