Acetic Acid → HCID 178468706, Verbindung

Beteiligte Stoffe

Reaktionsschritte

To a solution of the above-prepared 1-(4-methoxymethyl-2-phenyl-thiazol-5-yl)-ethanone (5.22 g, 21.12 mmole, 1.0 eq) in dry THF (100 ml) at −15° C. was added dropwise a solution of 1.0M potassium t-butoxide in THF (31.7 ml, 31.7 mmole, 1.5 eq) and the suspension stirred at room temperature under nitrogen for one hour. Diethyl oxalate (4.4 ml, 31.7 mmole, 1.5 eq) was added, the brown suspension diluted with additional THF (60 ml) and allowed to stir at room temperature for 30 minutes. The mixture was quenched by adding glacial acetic acid (3.2 ml, 2.6 eq). THF was removed in vacuo, and the residual oil was dissolved in absolute ethanol (175 ml) and treated with hydrazine monohydrate(1.4 ml, 30 mmole, 1.4 eq). This mixture was heated at 70° C. for 3 hours. The resulting yellow suspension was concentrated in vacuo leaving a residual oil that was dissolved in ethyl acetate. The organic phase was washed with water, saturated NaHCO3 and brine, then dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow oily solid. Silica gel chromatography using a gradient elution of (9:1)-(4:1) hexanes-ethyl acetate provided a yellow solid which was triturated with hexanes, filtered and driedin vacuo to give 3.69 g (51%)of the title compound as an off-white solid. 1H NMR(CDCl3): δ 1.4 (t, 3H), 3.5 (s, 3H), 4.4 (q, 2H), 4.8 (s, 2H), 7.0 (s, 1H), 7.4 (m, 3H), 7.9-8.0 (m, 2H).

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