The synthetic procedure for 5 was similar to that for 1, except that 4-formyl benzoic acid (0.38 g, 2.5 mmol) was used instead of 4-nitrobenzaldehyde. The crude product was purified using silica chromatograph with dichloromethane/cyclohexane mixture
The synthetic procedure for 5 was similar to that for 1, exceptthat 4-formyl benzoic acid (0.38 g, 2.5 mmol) was used instead of4-nitrobenzaldehyde. The crude product was purified using silicachromatograph with dichloromethane/cyclohexane mixture