58981-95-6Relevant articles and documents
Novel method for synthesis of some biologically active aminocoumarins
Mashelkar,Audi
, p. 258 - 261 (2008/09/21)
Nitration of coumarin 4-methyl acetates using concentrated HNO3 in solvents like chloroform or dichloromethane at lower temperature 'Cheparon effect' was found to occur only on aromatic part of coumarin. Yields of nitrocoumarins are almost quantitative and isomers were separated using column chromatographic technique. Reduction of the nitrocoumarins was carried out in environmentally friendly hydride transfer system using Pd/C as catalyst and formic acid or phosphorous acid as hydride generating reagent. Functional groups like -OH, Br, COCH3, -CH2COOH3 and lactone were not interfering in the reduction of nitro group to amino.
CONVENIENT SYNTHESIS OF A SIMPLE COUMARIN FROM SALICYLALDEHYDE AND WITTIG REAGENT (III): SYNTHESIS OF NITROCOUMARINS
Harayama, Takashi,Nakatsuka, Kazumitsu,Nishioka, Hiromi,Maurakami, Kyoko,Ohmori, Yukiko,et al.
, p. 2729 - 2738 (2007/10/02)
Reaction of nitrosalicylaldehydes (1) with carbethoxymethylenetriphenylphosphorane in Et2NPh, in Ph2O, and in the absence of solvent (neat) at 210-215 deg C was investigated.Reaction of 3-nitrosalicylaldehyde (1d) in Et2NPh afforded the benzoxazole (6) and the aminocoumarin (3e) along with the expected coumarin (3d).It was clarified that the origin of carbon-unit introduced for the formation of the benzoxazole ring came from the alkyl group of solvent.
