反应详情

4.00 g (15.9 mmol) of the above prepared [2-(3-methoxy-propyl)-phenoxy]-acetic acid ethyl ester was dissolved in 5.0 ml of TFAA and added slowly and carefully via dropping funnel to a mixture of 5 ml of TFAA and 4 ml of conc. HNO3 (65%) kept at −10° C.; the reaction was then allowed to proceed for additional 30 Min. Careful quenching with ice, twofold extraction with AcOEt, washing with NaHCO3 and brine, drying over magnesium sulfate, and evaporation of the solvents left a crude product which was purified by flash chromatography (SiO2, hexane/AcOEt=75/25) to deliver finally 3.00 g of the title compound as light brown oil, contaminated according to NMR with roughly 35% of the ortho-isomer which was separated after the next step.

1. additionadded slowly
2. customkept at −10° C.
3. customCareful quenching with ice, twofold extraction with AcOEt
4. washwashing with NaHCO3 and brine
5. dry with materialdrying over magnesium sulfate, and evaporation of the solvents
6. waitleft a crude product which
7. customwas purified by flash chromatography (SiO2, hexane/AcOEt=75/25)
8. customwas separated after the next step