5.05 g (0.0232 mol) of 3-(4-fluoro-phenoxy)-benzyl alcohol and 3.72 g (0.0232 mol) of 2,2,3,3-tetramethylcyclopropanecarboxylic acid chloride were dissolved in 100 ml of anhydrous toluene, and 2.3 g of pyridine, dissolved in 50 ml of anhydrous toluene, were added dropwise at 20°-25° C., while stirring. The reaction mixture was then stirred for a further 3 hours at 25° C. It was poured into 150 ml of water, to which 10 ml of concentrated hydrochloric acid had been added, and the organic phase was separated off and washed again with 100 ml of water. The toluene phase was then dried over sodium sulphate and the solvent was distilled off under a waterpump vacuum. Last residues of solvent were removed by brief incipient distillation at a bath temperature of 60° C./1 mm Hg. 6.5 g (81.9% of theory) of 2,2,3,3-tetramethyl-cyclopropanecarboxylic acid 3-(4-fluorophenoxy)-benzyl ester were obtained as a yellow oil with a refractive index nD20 of 1.5348.
