Convenient One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles from Arylaldehydes, Benzyl Alcohols, or Benzyl Halides with HMDS in the Presence of Molecular Iodine
A one-pot efficient procedure for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives in good to excellent yields by reaction between hexamethyldisilazane and arylaldehydes, benzyl alcohols, benzylhalides in the presence of molecular iodine has been developed. The remarkable advantages of this method are the simple workup procedure, high yields of products, and the availability of reagents.
A one-pot efficient procedure for the synthesis of 2, 4, 5-triaryl-1H-imidazole derivatives by the reactions of
hexamethyldisilazane and arylaldehydes in the presence of N-bromosaccharin (NBSa) is studied. This new method offers
several advantages, such as excellent yields, easy workup, short reaction times, and simple procedure.
One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles from Arylaldehydes, Benzyl Alcohols, or Benzyl Halides with Hexamethyldisilazane in Molten Tetrabutylammonium Bromide
作者:Javad Salehi、Mohammad Khodaei、Ahmad Khosropour
DOI:10.1055/s-0030-1258393
日期:2011.2
A simple and efficient method for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives in good to excellent yields by reaction between hexamethyldisilazane and arylaldehydes, benzyl alcohols, benzyl halides in molten tetrabutylammonium bromide as an inexpensive and non toxic solvent has been developed. The remarkable advantages of this method are the simple workup procedure, high yields of products, the use of an ionic liquid as a green solvent, and the availability of reagents.
Verfahren zur Herstellung von p-Nitrophenyl-imidazolen
申请人:BASF Aktiengesellschaft
公开号:EP0365907A1
公开(公告)日:1990-05-02
Verfahren zur Herstellung von in 2- und/oder 4- und/oder 5-Position durch p-Nitrophenyl und gegebenenfalls zusätzlich substituierten Imidazolen durch Umsetzung von in 2- und/oder 4- und/oder 5-Position durch Phenyl und gegebenenfalls zusätzlich substituierten Imidazolen mit Gemischen von Schwefelsäure und Salpetersäure, indem man die Reaktion in Gegenwart von Harnstoff durchführt.
The present invention relates to a composition comprising (i) a compound A that absorbs in the near visible- ultraviolet A (UVA) region and (ii) a compound B that absorbs in the ultraviolet B (UVB) region, wherein at least one of said compounds A or B is a compound of formula (I) wherein Y represents an optionally substituted aryl or styryl-aryl group, R1, R2, R3 and R4 independently of each other represent H, OH, ORa, NH2, NHRa, NRaRb, NO2 or halogen; wherein Ra and Rb independently of each other represent C1-C10 alkyl; and R5 and R6 independently of each other represent H, or alternatively R5 and R6 together form a C-C bond between the carbon atoms to which they are bound. The invention also relates to the use of said compound of formula (I) in the preparation of a photoprotective composition and to the related cosmetic treatment.