반응 #79972

반응 방정식

1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

spiro[2H-1-benzopyran-2,1′-cyclopropane]-6-carboxylic acid

8-cyclopropyl-3,4-dihydro-4,4-dimethyl

4-[(8-cyclopropyl-3,4-dihydro-4,4-dimethylspiro[2H-1-benzopyran-2,1′-cyclopropane]-6-yl)ethynyl]-2-fluoro-benzeneacetic acid methyl ester

Intermediate 49

4-[(8-cyclopropyl-3,4-dihydro-4,4-dimethylspiro[2H-1-benzopyran-2,1′-cyclopropane]-6-yl)ethynyl]-2-fluoro-benzeneacetic acid methyl ester

tert-butyl-4-hydroxy phenyl acetate

t-butyl-4-hydroxy-phenyl acetate

Reagent E

4-Hydroxy phenyl acetic acid-t-butyl ester

→

title compound

[4-(8-Ethyl-2,2,4,4-tetramethyl-chroman-6-yl-ethynyl) phenyl] acetic acid

용매

hexane

ethyl acetate

dichloromethane

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실험 절차

A solution of spiro[2H-1-benzopyran-2,1′-cyclopropane]-6-carboxylic acid, 8-cyclopropyl-3,4-dihydro-4,4-dimethyl-(Intermediate 49, 0.06 g, 0.22 mmol) in anhydrous dichloromethane (5 mL) was treated with tert-butyl-4-hydroxy phenyl acetate (Reagent E, 0.05 g, 0.22 mmol) followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.11 g, 0.22 mmol) and 4-dimethylaminopyridine (0.028 g, 0.22 mmol). The resulting solution was stirred at ambient temperature overnight. The reaction mixture was subjected to flash column chromatography over silica gel (230-400 mesh) using 7% ethyl acetate in hexane as the eluent to afford the title compound as a clear oil that solidified on standing (0.048 g, 48%).

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