[Synthesis]
Example 14A Ethyl 1-(4-bromophenyl)cyclopropanecarboxylate was synthesized as follows: first, 1.45 g (36.2 mmol) of sodium hydroxide (60% mineral oil dispersion) was suspended in 100 mL of anhydrous DMF. Subsequently, a mixture of 4.0 g (16.5 mmol) of ethyl p-bromophenylacetate with 6.5 g (34.6 mmol) of 1,2-dibromoethane was dissolved in 50 mL of anhydrous THF and this solution was added slowly and dropwise to the sodium hydride suspension. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the reaction mixture was diluted with ethyl acetate and washed sequentially with water and saturated sodium chloride solution. The organic phase was separated, dried with anhydrous magnesium sulfate, filtered and the filtrate concentrated. The residue was purified by preparative HPLC [column: Reprosil C18, 10 μm, 250 mm × 40 mm; mobile phase: 30% methanol/70% water to 100% methanol gradient elution, run time 25 min]. After HPLC analysis, the fractions containing the target product were combined and concentrated to give 1.15 g (26% yield) of the target product as a liquid. The product was characterized by GC-MS [Method 5] and 1H-NMR (400 MHz, DMSO-d6): GC-MS retention time Rt = 5.45 min; MS (ESIpos): m/z = 268/270 [M+]; 1H-NMR δ (ppm): 1.09 (t, 3H), 1.16-1.20 (m, 2H), 1.46-1.50 (m, 2H) 1.46-1.50 (m, 2H), 4.02 (q, 2H), 7.26-7.31 (m, 2H), 7.47-7.51 (m, 2H). |