Water → HCID 19045060, compound

Participants

Reaction Steps

A solution of diketene (57.71 mL, 748.2 mmol) was added dropwise over 2 h to a stirred solution of title compound of Step A (34.57 g, 149.6 mmol) and 4-dimethylaminopyridine (914 mg, 7.48 mmol) in dry tetrahydrofuran (450 mL) at room temperature under a nitrogen atmosphere. The reaction was allowed to stir at room temperature overnight. First, water was added to the reaction, and then the reaction mixture was poured into water. The mixture was saturated with sodium chloride and was extracted with ethyl acetate three times. The combined organic layers were dried (MgSO4), filtered, and the solvent was removed under reduced pressure to give a brown oil. The brown oil was suspended in 1-chlorobutane. The resultant precipitate was filtered from this suspension to afford the title compound of Step B as a brown solid melting at 136°-138° C. (21.67 g, 46%). 1H NMR (CDCl3): δ2.35 (s,3H), 2.41 (s,3H), 3.63 (s,2H), 7.69 (s,2H), 9.6 (br s, 1H).

Provenance & Evidence