Calcium Carbonate → 6-Methylphthalide

Beteiligte Stoffe

Reaktionsschritte

A heterogeneous, colorless solution of methyl 2-(bromomethyl)-5-methylbenzoate and regioisomer (27.2 mmol) and calcium carbonate (16.33 g, 163 mmol) in 1,4-dioxane (194 mL) and water (194 mL) was refluxed. After 5 hr, the reaction was cooled to room temperature. The insolubles were filtered, and the filtrate was concentrated in vacuo. The residue was extracted with CH2Cl2 (2×200 mL). The organic layers were combined, dried over MgSO4, and concentrated in vacuo to give an oil which was purified by flash chromatography using an ISCO 220 g column eluting with 10-50% EtOAc/hexanes. Appropriate fractions were collected and concentrated in vacuo to give the desired product (1.205 g, 8.13 mmol, 29.9% yield) as a white solid.

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