反应详情

A solution of 11 ml of titanium tetrachloride in 27 ml of carbon tetrachloride is added dropwise at -10° C. to 110 ml of anhydrous tetrahydrofuran. Once the addition is complete, a solution of 14.7 g of 4-chloro-4'-(methylsulphonyl)benzophenone (the preparation of which is described in the document W097/37984) in 50 ml of anhydrous tetrahydrofuran is added dropwise in keeping the temperature below 0° C. A mixture of 8.05 g of 2-phenyl-5(4H)-oxazolone, 16 ml of pyridine and 25 ml of anhydrous tetrahydrofuran is then added dropwise at 0° C. The mixture is stirred 2 hours at this temperature, then brought to ambient temperature and 50 ml of water are added. After decanting, the organic phase is washed with water then dried over magnesium sulphate and evaporated off under vacuum. The residue crystallises in an acetone/t-butyl methyl ether mixture and is chromatographed on silica in an acetone/dichloromethane mixture (0.3/10) to give 5 g of (E)-4-[1-(4-chlorophenyl)-1-[4-(methylsulphonyl)phenyl]methylene]-2-phenyl-5-oxazolone as crystals of melting point 226° C.

1. additionOnce the addition
2. additionis added dropwise
3. customthe temperature below 0° C
4. additionis then added dropwise at 0° C
5. custombrought to ambient temperature
6. customAfter decanting
7. washthe organic phase is washed with water
8. dry with materialthen dried over magnesium sulphate
9. customevaporated off under vacuum
10. customThe residue crystallises in an acetone/t-butyl methyl ether mixture
11. customis chromatographed on silica in an acetone/dichloromethane mixture (0.3/10)