反应详情

A mixture of the 4-iodo-2-phenylbenzoic acid methyl ester prepared in Example 21° C. (2.77 g, 8.20 mmol) in aqueous saturated lithium hydroxide (3 mL) and methanol (10 mL) was heated at 60° C. for 12 hours. The mixture was then acidified with concentrated HCl to pH about 2, and extracted twice with ethyl acetate (50 mL each). The combine extracts was washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was suspended in dichloromethane (10 mL), and oxalyl chloride (2.0 M in dichloromethane, 6.2 mL)was added, followed by a small drop of DMF. The mixture was stirred at room temperature for 1 hour, and then was concentrated in vacuo, followed by further drying under high vacuum for 10 minutes. To the residue was added dichloromethane (20 mL), L-methionine methyl ester hydrochloride (1.64 g, 8.05 mmol) and triethylamine (3.4 mL, 24.6 mmol). The reaction mixture was stirred at room temperature for 12 hours. The mixture was diluted with ether (50 mL), filtered through silica gel (30 g), and concentrated in vacuo. The crude product was purified by column chromatography (40:40:20 hexane-chloroform-ether) to give (4-iodo-2-phenylbenzoyl)methionine methyl ester (3.46 g, 90%). 1H NMR (300 MHz, CDCl3) δ 7.76 (m, 2H), 7.42 (m, 6H), 5.88 (br d, 1H), 4.65 (m, 1H), 3.68 (s, 3H), 2.05 (m, 2H), 2.00 (s, 3H), 1.90 (m, 1H), 1.73 (m, 1H).

1. extractionextracted twice with ethyl acetate (50 mL each)
2. washThe combine extracts was washed with brine
3. dry with materialdried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. additionoxalyl chloride (2.0 M in dichloromethane, 6.2 mL)was added
7. concentrationwas concentrated in vacuo
8. customby further drying under high vacuum for 10 minutes
9. stirringThe reaction mixture was stirred at room temperature for 12 hours
10. filtrationfiltered through silica gel (30 g)
11. concentrationconcentrated in vacuo
12. customThe crude product was purified by column chromatography (40:40:20 hexane-chloroform-ether)