Ethylene Glycol → 5-[1,3]Dioxolan-2-yl-N-methyl-N-propyl-isophthalamic acid

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Reaction Steps

Mix 5-formyl-N-methyl-N-propyl-isophthalamic acid ethyl ester (580 mg, 2.1 mmol), ethane-1,2-diol (0.35 mL, 6.3 mmol), and boron trifluoride diethyl etherate (0.2 mL, 1.6 mmol) in THF (5 mL) and stir for 1.5 h. Add additional ethane-1,2-diol (0.35 mL, 6.3 mmol) and stir for 20 min. Add 1 N NaOH (10 mL) and stir for 1 h. Add additional 5 N NaOH (1 mL) and stir for 30 min. Dilute the reaction mixture with water (10 mL) and wash with diethyl ether (2×10 mL). Acidify the aqueous layer with 0.5 N HCl to about pH=5. Extract with dichloromethane (3×20 mL), dry (sodium sulfate) and concentrate to give the title compound as a crude residue that is used in the next step without further purification.

Provenance & Evidence