On the Reaction of ?-Chlorobenzylic Cations with Isocyanates
作者:A. El-Hamid Ismail、A. Hamed、M. Taha Abdel-Aal、I. Zeid、M. Al-Talib、Q. Wang、J. C. Jochims
DOI:10.1002/prac.19923340804
日期:——
Isocyanates react as N-nucleophiles with alpha-chlorobenzylic cations (2) to give 1-oxoisoindolium salts (5). From the reaction of benzotrichlorides with SbCl5 and isocyanates the extremely reactive hexachloroantimonates 5 with R2 = Cl are isolated. Hydrolysis of these cyclic N-acyl iminium salts affords phthalimides 6. Reaction of 5 k with dimethylcyanamide gives the 2-azoniaallene salt 13. p-Tolyl isocyanate is Friedel-Crafts alkylated by p-chlorobenzotrichloride (1i) in the presence of SbCl5 to furnish the 1,3-oxadiazinium salt 7, which is hydrolyzed to give the benzophenone 9. With ethanol the acetals 10 and 11 are formed from 7.