Nitrogen → (2-(2-Methyl-[1,3]dioxolan-2-yl)oxazol-4-yl)methyl methanesulfonate

Participants

Reaction Conditions

Reaction Steps

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of (2-(2-methyl-[1,3]dioxolan-2-yl)oxazol-4-yl)methanol (235 mg, 1.27 mmol) in dry CH2Cl2 (10 mL) was treated at 0° C. with Et3N (0.24 mL, 1.68 mmol) followed by DMAP (16 mg, 0.13 mmol) and Ms-Cl (0.13 mL, 1.65 mmol). After stirring at 0° C. for 1 h, the reaction was quenched with water (10 mL). The org. layer was dried over MgSO4, filtered, and the solvents were removed under reduced pressure to give crude (2-(2-methyl-[1,3]dioxolan-2-yl)oxazol-4-yl)methyl methanesulfonate as a brown oil. The crude material was dissolved in dry DMF (6 mL) and treated with NaN3 (93 mg, 1.41 mmol) at 80° C. until completion of the reaction. 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 MgSO4, filtered and concentrated under reduced pressure to give crude 4-(azidomethyl)-2-(2-methyl-1,3-dioxolan-2-yl)oxazole as a brown oil. To a solution of the crude azide in THF (6 mL) were added polymer-supported Ph3P (1.2 eq.) and water (2 mL). The reaction mixture was stirred at 60° C. until completion of the reaction, cooled down to rt and filtered. The filtrate was partitioned between EA and aq. sat. NaHCO3 and the layers separated. The aq. layer was concentrated under reduced pressure, the residue triturated in EtOH and the solid filtered off. The filtrate was dried over Na2SO4, filtered and concentrated under reduced pressure to give the title compound as an orange oil. LC-MS-conditions 01: tR=0.31 min; [M+H]+=185.01.

Provenance & Evidence