Vinylidene chloride → Ethyl 5-chloro-1,2-oxazole-3-carboxylate

Beteiligte Stoffe

Reaktionsschritte

To a solution of ethyl chlorooximidoacetate (11.0 g, 72.6 mmol, 1 equiv) in 1,1-dichloroethylene (350 mL) was added Et3N (25.3 mL, 181 mmol, 2.5 equiv) in 1,1-dichloroethylene (100 mL) via addition funnel over 30 min. The reaction mixture was stirred at room temperature for 23 h, then was partitioned between water (150 mL) and CH2Cl2 (2×150 mL). The combined organic layers were dried over Na2SO4 and were concentrated. The residue was purified by flash column chromatography (10% EtOAc in hexanes) to give the title intermediate (4.49 g, 35%) as a pale yellow oil: IR (cm−1) 1735, 1436, 1253; 1H NMR (CDCl3) δ 1.45 (t, 3H, J=7.2), 4.49 (q, 2H, J=7.2), 7.29 (s, 1H).

Herkunft & Nachweise