have demonstrated the use of the room temperature ionicliquid, 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF 6 ), as an environmentally benign solvent for the preparation of 2-benzenesulfonyl-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ethyl ester derivatives through Pictet-Spengler reaction using phenyliodine(III) bis(trifluoroacetate) (PIFA) under mild conditions.
A Novel Cyclization of Electron Deficient N-Benzenesulfonyl-b-phenethylamines Using Ethyl Chloro(methylthio)acetate. Synthesis of Ethyl 1,2,3,4-Tetrahydroisoquinoline-1-carboxylates