Molecular iodine efficiently catalyzes the reaction of beta-naphthol and araldehydes on a preheated hot plate at 90-95 degrees C to give biologically active aryl-14H-dibenzo[a, j]xanthenes under solvent-free condition. The yields are excellent and the reactions go to completion within 15-20 min.

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Multi-membered N-heterocycles R 0690 Synthesis of 1,5-Benzodiazepine Derivatives Catalyzed by Zinc Chloride. -Zinc chloride is a useful catalyst for the cyclocondensation of ketones with o-phenylenediamine. -(PASHA*, M. A.; JAYASHANKARA, V. P.; Heterocycles 68 (2006) 5, 1017-1023; Dep. Stud. Chem., Cent. Coll., Bangalore Univ., Bangalore 560 001, India; Eng.) -Mais 40-176

Arylnitro compounds are reduced to the corresponding azoarenes and/or arylamines by aluminium metal in the presence of sodium hydroxide in methanol in high yields under influence of power ultrasound (35 kHz) at 25 degrees C.

This paper describes the combustion synthesis of a-Fe 2 O 3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes. The combustion derived a-Fe 2 O 3 nanopowder was characterized by powder X-ray diffraction (PXRD), Braunauer, Emmett and Teller (BET) surface area, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Highly efficient, three-component condensation of aromatic aldehyde, malanonitrile and 4-hydroxycoumarin catalyzed by a-Fe 2 O 3 nanoparticles at room temperature is described. The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes. The reactions are rapid, clean, and the products with good yield and high purity. #