Hydrochloric Acid → Methyl 2-(6-methoxy-1H-inden-3-yl)butanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

An oven dried 5-L four-necked round-bottomed flask was fitted with a thermometer, a condenser, an addition funnel, and a mechanical stirrer. Under Ar protection, a suspension of 5-methoxy-1-indanone (80.0 g, 494 mmol), Zn powder (Lancaster, 56.2 g, 865 mmol) in 2 L anhydrous THF was stirred at 60° C. (internal temperature), while a solution of methyl bromobutyrate (134.1 g, 741 mmol) in 400 mL anhydrous THF was added slowly through an addition funnel. After completion of the addition, the reaction mixture was stirred at 60° C. (internal temperature) for 1 hour. The reaction was followed by TLC analysis of aliquots following 1N aqueous HCl work-up. After the reaction was completed, it was cooled in an ice-water bath followed by slow addition of 3 L of 1N HCl solution. The pot temperature was kept below 20° C. The mixture was then extracted with 1 L EtOAc. The organic layer was washed with water until pH 6.0-7.0, then saturated NaCl solution, and dried over Na2SO4. The product (127 g, >99%), a yellow oil, was obtained after solvent removal and drying under vacuum. 1H NMR (DMSO-d6) δ 7.28 (d, 1H), 7.05 (d, 1H), 6.82 (dd, 1H), 6.22 (s, 1H), 3.72 (s, 3H), 3.60 (m, 1H), 3.58 (s, 3H), 3.28 (s, 2H), 1.95 (m, 1H), 1.80 (m, 1H), 0.88 (t, 3H).

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