Nitrogen → 2-(5-Chloromethyl-thiophen-2-yl)-2-methyl-[1,3]dioxolane

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Reaction Steps

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of [5-(2-methyl-[1,3]dioxolan-2-yl)thiophen-2-yl]-methanol (5.00 g, 25.0 mmol) in dry CH2Cl2 (46 mL) was treated at 0° C. with Et3N (4.5 mL, 32.5 mmol) followed by DMAP (305 mg, 2.5 mmol) and Ms-Cl (2.3 mL, 30.0 mmol). After stirring at rt for 2 h, the reaction was quenched with water (50 mL). The org. layer was dried over MgSO4, filtered, and the solvents were removed under reduced pressure to give crude 2-(5-chloromethyl-thiophen-2-yl)-2-methyl-[1,3]dioxolane as a yellow oil. Part of this crude material (953 mg, 4.36 mmol) was dissolved in dry DMF (15 mL) and treated with NaN3 (859 mg, 13.08 mmol) at 80° C. for 24 h. The reaction mixture was then cooled down to rt and partitioned between EA and water. The layers were separated and the org. layer dried over Na2SO4, filtered and concentrated under reduced pressure to give crude 2-azidomethyl-5-(2-methyl-[1,3]dioxolan-2-yl)thiophene as a yellow oil. LC-MS-conditions 02: tR=0.97 min; [M+H]+=226.50.

Provenance & Evidence