Rashmi Pundeer

An Improved Iodine(III) Mediated Method for Thiocyanation of 2-Arylindan-1,3-diones, Phenols, and Anilines

Abstract An improved method for thiocyanation of 2-arylindan-1,3-diones, phenols, and anilines using a reagent combination of (dichloroiodo)benzene and potassium thiocyanate in dry dichloromethane is described.

One-Pot Synthesis of Some New Semicarbazone, Thiosemicarbazone, and Hydrazone Derivatives of 1-Phenyl-3-Arylpyrazole-4-Carboxaldehyde from Acetophenone Phenylhydrazones Using Vilsmeier–Haack Reagent

Abstract Semicarbazone derivatives 3 of 1,3-diphenylpyrazole-4-carboxaldehyde have been synthesized in high yields through a one-pot procedure involving acetophenone phenylhydrazones 1 subjected to Vilsmeier double formylation and workup under new conditions (i.e., treatment with semicarbazide followed by sodium bicarbonate). This method is even suitable for preparing other derivatives (i.e., thiosemicarbazones 4 and hydrazones 5) in high yields.

A Facile Synthesis of Thiazole‐2(3H)‐thiones Through [Hydroxy(tosyloxy)iodo]benzene

Abstract A one‐pot facile synthesis of thiazole‐2(3H)‐thiones (4) has been achieved by hypervalent iodine oxidation of ketones (1) using [hydroxy(tosyloxy)iodo]benzene, followed by the treatment of the reaction mixture with dithiocarbamate salts (3). The intermediate α‐tosyloxyketones (2) have also been isolated and converted to the target compounds.

Synthesis and evaluation of antibacterial and antifungal activities of new (Z)-3-bromo-4-(1,3-diaryl-1H-pyrazol-4-yl)but-3-en-2-ones and 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1,3-diaryl-1H-pyrazoles

Bromination of 4-(1, 3-diaryl-1H-pyrazol-4-yl) but-3-en-2-ones, triggered by a combination of potassium bromide and cerium(IV) ammonium nitrate in a biphasic system consisting of water and dichloromethane furnishes the corresponding monobromo compounds 2 directly, instead of the expected dibromo compounds. The α-bromo compounds 2 were utilized as efficient precursors for the synthesis of several bipyrazolyl derivatives, 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1, 3-diaryl-1H-pyrazoles (3). All the α-bromoenones 2 and bipyrazoles 3 are new compounds and their identity was established by m.p., spectral and analytical data. The new products 2 and 3 were tested for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis (Gram positive), Escherichia coli, and Pseudomonas aeruginosa (Gram negative) and antifungal activity against Aspergilus flavus and Aspergillus niger. The antimicrobial activity of the tested compounds is compared with the commercially available antibiotic, ciprofloxacin and antifungal agent, fluconazole.

α,α-Dibromoacetophenones mediated synthesis of some new 7H-7-alkoxy-3-alkyl/phenyl-6-aryl-s-triazolo[3,4-b][1,3,4]thiadiazines and their antimicrobial evaluation

A series of new 7H-7-alkoxy-3-alkyl/phenyl-6-aryl-s-triazolo[3,4-b][1,3,4]thiadiazines (3, 4) were synthesized by the reaction of various α,α-dibromoacetophenones 1 with 3-alkyl/phenyl-4-amino-5-mercapto-s-triazoles (2) in different alcoholic solvents in good yields. All the newly synthesized compounds (3, 4) were screened for their in vitro antibacterial and antifungal activity. Biological activities of these compounds were compared with those of the commercially available antibiotic, ciprofloxacin and antifungal agent, amphotericin-B. The title compounds showed good activity against the Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis and the yeasts, Saccharomyces cerevisiae and Candida albicans.