Microwave accelerated Gewald reaction: synthesis of 2-aminothiophenes

Microwave-promoted synthesis of 2-aminothiophenes by multicomponent reactions of a ketone with an active nitrile and elemental sulfur under KF-alumina catalysis is described.     

Single and multiple ionization of N2 molecules by intense light fields of femtosecond duration

We report studies on the multiple ionization of the N₂ molecule using intense, femtosecond laser pulses. We present details of the experimental characterisation of the light pulses and analysis and detection of the ions produced. Precautions to be taken in intense field ionization experiments are discussed. We illustrate the retrieval of information about different aspects of the ionization process (such as, kinetic energies of the fragments produced, dissociation bond lengths and information on the precursors to fragmentation) using coincidence techniques. We report results of the first measurements of the angular distribution of a highly charged fragment, N³⁺.     

Pluronic F-127: An Efficient Delivery Vehicle for 3-(1'-hexyloxy)ethyl-3-devinylpyropheophorbide-a (HPPH or Photochlor)

To determine the impact of delivery vehicles in photosensitizing efficacy of HPPH, a hydrophobic photosensitizer was dissolved in various formulations: 1% Tween 80/5% dextrose, Pluronic P-123 and Pluronic F-127 in 0.5%, 1% and 2% phosphate buffer solutions (PBS). HPPH was also conjugated to Pluronic F-127, and the resulting conjugate (PL-20) was formulated in PBS. Among the different delivery vehicles, only Pluronic P-123 displayed significant vehicle cytotoxicity, whereas Pluronic F127 was nontoxic. Compared to PL-20, HPPH formulated in Tween80 and Pluronic F-127 showed higher cell-uptake, but lower long-term retention in Colon26 cell compared to PL-20. The higher retention of PL-20 was similarly observed during in vivo uptake with BALB/c mice baring Ct26 tumors. In contrast to the in vitro uptake experiments, PL-20 showed slightly higher uptake compared to HPPH formulated in Tween or Pluronic-F127. A significant difference in pharmacokinetic profile was also observed between the HPPH-Pluronic formulation and PL-20. Under similar in vivo treatment parameters (drug dose 0.47 µmol kg⁻¹, light dose: 135 J cm⁻² at 24 h post-injection of PS), HPPH formulated either in Tween or Pluronic F-127 formulation showed similar in vivo PDT efficacy (20–30% tumor cure on day 60), whereas PL-20 showed 40% tumor cure (day 60).     

Facile Synthesis of Pyrazoline Derivatized Amides via Sydnone Ring Cleavage

In the present investigation, we have utilized 3‐[3′‐(5″‐aryl‐2″‐pyrazolin‐3″‐yl)]phenylsydnones 1a–c to couple two biodynamic moieties in amide derivatives 7 , 8 , 9 , 10 . The compounds 1a–c were brominated to 4‐bromo‐3‐[3′‐(5″‐aryl‐2″‐pyrazolin‐3″‐yl)]phenylsydnone 2 , which were further reacted with secondary amines to form the title compounds. These novel molecules were subjected to antitubercular activity against Mycobacterium tuberculae (H₃₇R_v) and antioxidant activity assay.     

Synthesis of 5,7-Dihydroxy-6-methoxy-2-(2-hydroxy-4-methoxyphenyl)-4H-1-benzopyran-4-one and Reassignment of Structure of Tamaridone1

The proposed structure of a new flavone, tamaridone, isolated from Tamarix dioica Roxb is untenable on the basis of comparison with its synthetic sample. Its structure has been now revised to 5,7-dihydroxy-8-methoxy-2-(3-hydroxy-4-methoxyphenyl)-4H-1-benzopyran-4-one by careful spectral studies.     

New Effective Synthetic Method for Preparation of N,N-Dichlorocarbamates

A rapid, efficient, economical, and easy-to-scale method for the effective conversion of carbamates to corresponding N,N-dichlorocarbamates by using sodium hypochlorite in acidic medium has been described. N,N-Dichlorocarbamates were obtained in quantitative yield through a simple workup in reduced reaction time.