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An efficient synthesis of 4-arylcoumarins has been accomplished via Kostanecki reactions of 2-hydroxybenzophenones with acetic anhydride employing DBU at ambient temperature. Using the same strategy, several 2-acyloxybenzophenone derivatives were readily converted to 3,4-difunctionalized coumarins. This protocol offers a notable improvement in reaction conditions for coumarin synthesis and takes advantage of its synthetic capability, especially for highly functionalized 4-arylcoumarins with structural diversity.

The direct reductive amination of 2,5-diformylfuran (DFF) with ammonia to 2,5-bis(aminomethyl)furan (BAF) was demonstrated, for the first time, over the commercial type Nickel-Raney and acid treated Nickel-Raney catalysts. The effects of reaction parameters such as reaction medium, temperature and hydrogen pressure were described. The acid treated Nickel-Raney catalyst exhibited the highest BAF yield in the THF-water mixed reaction medium. The relatively higher Ni 0 species composition and larger surface area of the acid treated Nickel-Raney catalyst with specific reaction conditions contributed greatly to the BAF formation. The oligomeric species, such as furanic imine trimers and tetramers confirmed by MALDI-MS analysis were presented as the intermediates of DFF reductive amination.

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Pyrazole derivatives R 0180Identification of Antitumor Activity of Pyrazole Oxime Ethers. -A variety of multi-functionalized pyrazole oxime ethers are synthesized and evaluated for their cytotoxicity. Phenoxypyrazole derivatives (I) display cytotoxicity comparable to doxorubicin. -(PARK, H.-J.; LEE, K.; PARK, S.-J.; AHN, B.; LEE, J.-C.; CHO, H.; LEE*, K.-I.; Bioorg. Med. Chem. Lett. 15 (2005) 13, 3307-3312; Bio-Org. Sci. Div., Korea Res. Inst. Chem. Technol., Taejon 305-600, S. Korea; Eng.) -A. Forchert 42-140