Bromide ion → 4-(4-Nitro-pyrazol-1-ylmethyl)-thiazole-2-carboxylic acid ethyl ester

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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 4-chloromethyl-thiazole-2-carboxylic acid ethyl ester (1.84 g, 8.93 mmol) in acetone (20.0 mL) was treated, under inert atmosphere (N2) with K2CO3 (6.23 g, 44.66 mmol) followed by 4-nitro-1H-pyrazole (1.00 g, 8.93 mmol) and TBA bromide (576 mg, 1.79 mmol). The resulting mixture was stirred at rt overnight. Water (40 mL), followed by EA (50 mL) were added. The aq. layer was extracted with EA (50 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 (50:50 hept-EA) gave the title compound as a yellow oil. TLC: rf (50:50 hept-EA)=0.30. LC-MS-conditions 02: tR=0.90 min; [M+H]+=283.25.

Provenance & Evidence