The reaction mixture was stirred for 3h at the same temperature with simultaneous adjustment of pH≈ 8. The TEA hydrochloride was filtered off, excess sol-vent distilled off and residue in, mainly, ethyl acetate (EtOAc) was washed with HCl (1 N, 3 × 20 ml), Na-HCO3 (5%, 3 × 20 ml), H2O (3 × 20 ml) and dried over anhydrous sodium sulfate, excess solvent was distilled off to get 3a, b and 3 g in good yields (Table 1).