Ethyl 4-iodobenzoate → Ethyl 4-(3,3-dimethylcyclobutanecarbonyl)benzoate

関与物質

反応条件

反応手順

To a −40° C. solution of ethyl 4-iodobenzoate (2.30 g, 8.30 mmol) in tetrahydrofuran (20 mL) was added isopropylmagnesium chloride-lithium chloride (7.1 mL, 1.3 M in THF, 9.2 mmol) dropwise. The mixture was stirred for 1 hour at −40° C. Copper(I) iodide (476 mg, 2.50 mmol) was then added and the reaction was allowed to warm to −10° C. and stir for 20 minutes. The solution was cooled again to −40° C. and a solution of the previously prepared 3,3-dimethylcyclobutanecarbonylchloride (1.54 g, 10.5 mmol) in tetrahydrofuran (10 mL) was added dropwise. The reaction was allowed to warm to 0° C. and stir for 2 hours. The reaction was quenched with 1 N aqueous hydrochloric acid and extracted with ethyl acetate (3×15 mL). The combined organics were dried over sodium sulfate, filtered, and concentrated. Purification by flash column chromatography gave ethyl 4-(3,3-dimethylcyclobutanecarbonyl)benzoate (1.80 g, 83%) as a pale yellow solid. 1H NMR (400 MHz, CDCl3, δ): 8.15 (d, J=8.4 Hz, 2H), 7.98 (d, J=8.4 Hz, 2H), 4.20-4.47 (m, 2H), 3.89-3.98 (m, 1H), 2.22-2.27 (m, 2H), 2.09-2.15 (m, 2H), 1.45 (t, J=7.2 Hz, 3H), 1.32 (s, 3H), 1.13 (s, 3H).

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