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

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 [4-(2-methyl-[1,3]dioxolan-2-yl)-thiophen-2-yl]-methanol (256 mg, 1.28 mmol) in dry CH2Cl2 (5.0 mL) was treated at 0° C. with Et3N (0.23 mL, 1.64 mmol) followed by DMAP (16 mg, 0.13 mmol) and Ms-Cl (0.12 mL, 1.55 mmol). After stirring at 0° C. for 30 min and at rt for 1 h, the reaction mixture was quenched with water (10 mL), extracted with CH2Cl2 (10 mL) and the combined org. extracts were dried over Na2SO4, filtered, and the solvents were removed under reduced pressure to give crude 2-(5-chloromethyl-thiophen-3-yl)-2-methyl-[1,3]dioxolane (TLC:rf (1:1 EA-Hept)=0.61). A solution of the crude material in DMF (3 mL) was treated at rt with a solution of (4-nitro-2H-[1,2,3]triazole (124 mg, 1.07 mmol) in DMF (2.0 mL) pre-treated for 30 min with DIPEA (0.40 mL, 2.34 mmol). The resulting mixture was stirred for two weeks at rt. Water (10 mL), followed by EA (10 mL) were added. The org. extract was washed with water (10 mL), dried over Na2SO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (hept to 1:1 hept-EA) gave the title compound as a yellow oil: TLC:rf (1:1 hept-EA)=0.48.

Provenance & Evidence