反应详情

2.78 g (0.00526 mol) of 2-ethyl-3-methoxy-benzoic acid N′-[2-(tert-butyl-dimethyl-silanyloxy)-1,1-dimethyl-ethyl]-N′-(3,5-dimethyl-benzoyl)-hydrazide were dissolved in 24 mL of THF. The mixture was cooled in an ice bath and 6.0 mL (0.006 mol) of a 1 M tetrabutyl ammonium fluoride-solution in THF were added. The reaction was stirred at room temperature for 5-6 hours, and then 100 mL of Et2O were added and the reaction mixture was poured into ice water in a separatory funnel. The aqueous layer was further extracted twice with 25 mL of Et2O and the total ether layer was dried and concentrated. TLC of the product showed a new product (Rf 0.20) below some of the starting material. The product was purified by chromatography, eluting with 40-50% ethyl acetate/hexane to yield 1.42 g of pure 3,5-dimethyl-benzoic acid N′-[1-(2-ethyl-3-methoxy-phenyl)-vinyl]-N-(2-hydroxy-1,1-dimethyl-ethyl)-hydrazide. (67% yield). TLC: Rf=0.20. 1H NMR (CDCl3, 300 MHz) δ (ppm): 7.1-6.8 (m, 5H), 6.0 (d, 1H), 4.3 (d, 1H), 3.78 (s, 3H), 3.5 (d 1H), 2.4 (d, 1H) 2.29 (s, 6H), 2.2 (d, H), 1.56 (s, 3H), 1.45 (s, 3H), 1.00 (t, 3H).

1. temperatureThe mixture was cooled in an ice bath
2. extractionThe aqueous layer was further extracted twice with 25 mL of Et2O
3. dry with materialthe total ether layer was dried
4. concentrationconcentrated
5. customThe product was purified by chromatography
6. washeluting with 40-50% ethyl acetate/hexane