Trifluoroacetic anhydride → [1-Oxo-2-(3-hydroxyphenyl)-2-methyl-6,7-dichloro-5-indanyloxy]acetic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Ethyl(1-oxo-2-phenyl-2-methyl-6,7-dichloro-5-indanyloxy)acetate (18.95 g., 0.05 mole) dissolved in trifluoroacetic acid (100 ml.) is added portionwise at less than 10° C. to a stirred mixture of lead tetrakistrifluoroacetate (0.055 mole) prepared by stirring lead oxide (37.5 g.), trifluoroacetic acid (85 ml.) and trifluoroaceticanhydride (75 g.) at 25° C. for 96 hrs. After stirring the reaction mixture at 25° C. for 6 hours it is poured into crushed ice-water (1 l.) to precipitate 19.7 g. of a mixture of esters which is hydrolyzed by heating at reflux with ethanol (400 ml.) -water (250 ml.)-10 N sodium hydroxide solution (40 ml.) for 3/4 hr. On addition to crushed ice-water (1 l.)-12 N hydrochloric acid (50 ml.) a gummy product precipitates, is extracted with ether then concentrated to give 60% of [1-oxo-2-(3-hydroxyphenyl)-2-methyl-6,7-dichloro-5-indanyloxy]acetic acid and 20% of the 4-hydroxyphenyl derivative. Crystallization from acetic acid gives 2.6 g. of [1-oxo-2-(3-hydroxyphenyl)-2-methyl-6,7-dichloro-5-indanyloxy]acetic acid, m.p. 248°-255° C.

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