Nitrogen → HCID 87207820, compound

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 (100 mg, 0.50 mmol) in dry CH2Cl2 (3.0 mL) was treated at 0° C. with Et3N (0.10 mL, 0.71 mmol) followed by DMAP (6 mg, 0.05 mmol) and Ms-Cl (0.05 mL, 0.64 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 methanesulfonic acid 4-(2-methyl-[1,3]dioxolan-2-yl)-thiophen-2-ylmethyl ester which was dissolved in acetone (5.0 mL) and treated with K2CO3 (349 mg, 2.50 mmol) followed by 4-nitro-1H-pyrazole (63 mg, 0.50 mmol) and TBA bromide (32 mg, 0.10 mmol). The reaction mixture was stirred at rt until completion. The solvent was removed under reduced pressure and water (10 mL) followed by EA (10 mL) were added. The aq. layer was extracted with EA (10 mL) and the combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (9:1 hept-EA) gave the title compound as a pale yellow oil. TLC: rf (1:1 hept-EA)=0.49. LC-MS-conditions 02: tR=0.95 min.

Provenance & Evidence