(2-Bromoethyl)benzene

65.5%; 31.2% With caesium carbonate; In N,N-dimethyl-formamide; for 24h;Product distribution / selectivity; 430 mg(2.5 mM) of 4-nitro-lH-pyrazole-3-carboxylic acid methyl ester was dissolved in 4 ml of N,N-dimethylformamide, to which 0.41 ml (3 mM) of (2-bromoethyl)benzene and 1.6 g (5.0 mM) of cesium carbonate were EPO <DP n="24"/>added dropwise, and the mixture was stirred under a nitrogen atmosphere for a day. The solvent was distilled off under reduced pressure, and the resultant was extracted with ethyl acetate and brine. The organic solvent layer was dried over anhydrous sodium sulfate, filtered, and then distilled under reduced pressure. The resulting impure compound was purified by column chromatography (hexane : ethyl acetate = 5 : 1), to obtain 506 mg (65.5%) of the title compound and 218 mg (31.2%) of the compound of Preparative Example 10.1H NMR(300MHz, CDCl3) delta 3.20(t, J= 7.0 Hz, 2H), 3.99(s, 3H), 4.39(t, J= 7.0 Hz, 2H), 7.03~7.08(m, 2H), 7.21~7.35(m, 3H), 7.78(s, IH).; 430 mg (2.5 mM) of 4-nitro-lH-pyrazole-3-carboxylic acid methyl ester was dissolved in 4 ml of N,N-dimethylformamide, to which 0.41 ml (3 mM) of (2-bromoethyl)benzene and 1.6 g (5.0 mM) of cesium carbonate were added dropwise, and the resulting mixture was stirred under a nitrogen atmosphere for a day. The solvent was distilled off under reduced pressure, and the resultant was extracted with ethyl acetate and brine. The organic solvent layer was dried over anhydrous sodium sulfate, filtered, and then distilled under reduced pressure. The resulting impure compound was purified by column chromatography (hexane : ethyl acetate = 5 : 1), to obtain 218 mg(31.2%) of the title compound and 506 mg (65.5%) of the compound of Preparative Example 1. 1H nuMR(300MHz, CDCl3) delta 3.13(t, J= 7.1 Hz, 2H), 3.82(s, 3H), 4.52(t,J= 7.1 Hz, 2H), 7.00~7.05(m, 2H), 7.22~7.64(m, 3H), 8.05(s, IH).