反应详情

(2,4-Dihydroxy-phenyl)-(2-hydroxy-4-nitro-phenyl)-methanone (395) (0.255 g, 0.927 mmol) was dissolved in warm AcOH (10 mL) and TiCl3 (2.0 M solution in aqueous 1M HCl, 5 mL) was added portion wise over a period of 2 hours until the color of the solution remained purple. TLC (Rf: 0.5 compared to Rf: 0.35 for compound 395 in 1:1 hexane/EtOAc, single spot) indicated complete reaction at this point. The mixture was concentrated to remove nearly all the AcOH. The mixture was diluted with EtOAc (100 mL), washed with NaHCO3 (aqueous sat., 500 mL) and brine (500 mL) via extraction, dried over MgSO4 and concentrated under reduced pressure. Purification by flash chromatography on silica gel using a gradient of hexane and EtOAc (eluding with 15–100% EtOAc/hexane in 30 minutes) gave the desired product (396) as a yellow/orange oil (0.067 g, 0.273 mmol, 29.4% yield). LC-MS (ESI): (exact mass: 245.07) m/e=246.2 [M+1]+.

1. customreaction at this point
2. concentrationThe mixture was concentrated
3. customto remove nearly all the AcOH
4. additionThe mixture was diluted with EtOAc (100 mL)
5. washwashed with NaHCO3 (aqueous sat., 500 mL) and brine (500 mL) via extraction
6. dry with materialdried over MgSO4
7. concentrationconcentrated under reduced pressure
8. customPurification by flash chromatography on silica gel using a gradient of hexane and EtOAc (eluding with 15–100% EtOAc/hexane in 30 minutes)