Hydrochloric Acid → HCID 54749146, compound

Participants

Reaction Steps

Ethyl 3-[2-[2-(ethyloxy)-1-methyl-2-oxoethylidene]-1-(phenylmethyl)hydrazino]-3-oxopropanoate. Ethyl pyruvate (0.324 g, 2.79 mmol) was added to a stirred mixture of benzylhydrazine dihydrochloride (0.551 g, 2.82 mmol), diisopropylethylamine (1.00 mL, 5.74 mmol) and dichloromethane (10 mL). Magnesium sulfate (excess) was added and the mixture stirred 0.5 h, then loaded onto a short column of silica gel and the product eluted (50% ethyl acetate/hexane). After evaporation of the solvent, the crude hydrazone (0.339 g) was dissolved in tetrahydrofuran (20 mL) and sodium hydride (0.075 g of a 60% oil suspension, 1.88 mmol) added with stirring. The mixture was stirred 20 min, then ethyl 3-chloro-3-oxopropionate (0.235 mL, 1.84 mmol) injected dropwise and stirring continued at room temperature 10 min and at 60° C. for 0.5 h. Further sodium hydride (0.075 g of a 60% oil suspension, 1.88 mmol) was added and stirring continued at 65° C. for 0.5 h. The mixture was cooled, poured into 0.1M aqueous hydrochloric acid (100 mL) and extracted with ethyl acetate. The extracts were dried (MgSO4) and evaporated under reduced pressure. Ethyl pyruvate (0.324 g, 2.79 mmol) was added to a stirred mixture of the residue in dichloromethane (10 mL) and magnesium sulfate. After 2 h, the mixture was chromatographed (silica gel, 20-50% ethyl acetate/hexane) to give the title compound (0.205 g, 22%) as a gum. LCMS (ES+) m/z 335 (MH+).

Provenance & Evidence