Potassium Carbonate → 5-[2-(tert-butoxycarbonyl-ethyl-amino)-propyl]-benzo[1,3]dioxole-2-carboxylic Acid Ethyl Ester

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Reaction Conditions

Reaction Steps

To 2 g (6.7 mmol) of 2C was added 40 mL of anhydrous DMF followed by 3.5 g (25 mmol) of anhydrous K2CO3, 5 g of 3 A° molecular sieves and 3.2 mL (25 mmol) of ethyl dibromoacetate. The reaction mixture was heated at 120° C. for 3 hours under argon atmosphere and then concentrated under reduced pressure. To the residue 75 mL of ethyl acetate were added and filtered. To the filtrate 75 mL of water were added and transferred to a separatory funnel. The organic layer was separated, and the aqueous layer was extracted with 5×75 mL of ethyl acetate. All the organic layers were combined, dried (anhydrous Na2SO4), and concentrated to dryness. The residue was purified by silica gel column chromatography using 10% ethyl acetate in hexane to give 954 mg (5.3 mmol, 37%) of 2D as a colorless gum (M+Na, 402).

Provenance & Evidence