Study on Synthesis ofortho-Hydroxyl AromaticN-tert-Butylsulfinyl Imines under Microwave Irradiation

Abstract

Chiral N-tert-butanesulfinyl imines have been shown to be important intermediates for asymmetric synthesis in recent years. Eleven new (R,E)-N-(2-hydroxybenzylidene)-tert-butyl-sulfinamides (3) were synthesized from salicylaldehydes 1 and chiral tert-butanesulfinamide 2 under microwave irradiation in moderate to good yields. The reaction could work well in the mixture of KHSO 4 /PhMe or Cs 2 CO 3 /CH 2 Cl 2 . And the results show that the KHSO 4 /PhMe reaction system is helpful for the salicylaldehydes with electron-donating group; however, the Cs 2 CO 3 /CH 2 Cl 2 reaction system is applicable to the salicylaldehydes with electron-deficient group and steric hindrance group. The structures of these new compounds were determined by 1 H NMR, 13 C NMR, IR and HRMS.