反应详情

[4-(Pyridin-2-ylmethoxy)-phenyl]-hydrazine dihydrochloride (75 g), 5-tert-butylsulfanyl-2,2-dimethyl-4-oxo-pentanoic acid ethyl ester (64 g), NaOAc (40 g) in toluene (800 mL) and HOAc (400 mL) was stirred at room temperature for 3 days. In one aspect, 5-tert-butylsulfanyl-2,2-dimethyl-4-oxo-pentanoic acid ethyl ester was prepared according to the procedures described in U.S. Pat. No. 5,288,743 issued Feb. 22, 1994. In another aspect, 5-tert-butylsulfanyl-2,2-dimethyl-4-oxo-pentanoic acid ethyl ester was prepared as outlined herein. The mixture was poured into water and made basic with solid Na2CO3. The mixture was extracted with EtOAc (×3), then washed with water (×2), brine, dried (MgSO4), filtered and concentrated to give a dark red-black oil. Column chromatography of the mother liquor (silica gel packed in hexanes; eluting with hexane then hexane-EtOAc 9:1 rising to 4:1) afforded 68 g of the title compound, as a yellow solid.

1. extractionThe mixture was extracted with EtOAc (×3)
2. washwashed with water (×2), brine
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customto give a dark red-black oil
7. washeluting with hexane