Nitrogen → [2-(5-Acetyl-thiophen-2-ylmethyl)-thiazol-4-yl]-carbamic acid tert-butyl ester

Participants

Reaction Steps

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 2-(5-acetyl-thiophen-2-ylmethyl)-thiazole-4-carboxylic acid (1.95 g, 7.29 mmol) in a mixture of toluene (20 mL) and t-butanol (10.3 mL) was treated at rt with Et3N (1.17 mL, 8.90 mmol) and DPPA (1.65 mL, 7.66 mmol). After stirring at rt for 5 min, the reaction mixture was stirred at 90° C. for 2 h. Cuprous chloride (112 mg, 1.09 mmol) was then added and the reaction mixture was stirred under reflux for 1 h. The reaction was allowed to cool down to rt and EA (50 mL) was added followed by NaHCO3 (50 mL). The aq. layer was extracted twice with EA (50 mL) and the combined org. layers were washed with brine (100 mL), dried over MgSO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (6:4 hept-EA) gave the title compound as an orange oil. TLC: rf (6:4 hept-EA)=0.35. LC-MS-conditions 02: tR=1.02 min, [M+H]+=339.42.

Provenance & Evidence