Cesium carbonate → tert-butyl 2-{[1-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-7-yl]oxy}ethylcarbamate

Participants

Reaction Steps

Using a modification on the procedure described in Part L of Example 2, 1-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-7-ol (8.50 g, 23.8 mmol) was treated with tert-butyl 2-iodoethylcarbamate (7.10 g, 26.2 mmol) and cesium carbonate (11.62 g, 35.67 mmol) in DMF (120 mL). During the workup, after the reaction mixture was concentrated under reduced pressure, the residue was treated with water (75 mL) and stirred for 30 minutes. A precipitate was isolated by filtration and washed with diethyl ether to yield 8.7 g of tert-butyl 2-{[1-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-7-yl]oxy}ethylcarbamate as an off-white solid, mp 152-153° C.

Provenance & Evidence