Hydrochloric Acid → Methyl 4-(acetylamino)-1-cyclopentene-1-carboxylate

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Reaction Conditions

Reaction Steps

(±)-cis-Methyl 4-acetamido-2-cyclopentene 1-carboxylate [S. Daluge and R. Vince, J. Org. Chem. 1978. 43, 2311](3.90 g, 21.3 mmol) was dissolved in dry methanol (25 mL) and added to a solution of sodium methoxide prepared from sodium (0.98 g, 43 m.equiv.) and dry methanol (150 mL). This solution was stirred at 25° C. for 2.0 hours and then neutralized with 1 N hydrochloric acid. The solution was concentrated to 40 mL and extracted with chloroform (3×75 mL). The chloroform was dried (MgSO4) and evaporated to colourless glass (3.9 g). Chromatography on silica gel with 1-2% methanol-chloroform gave title compound as white crystals (4.33 g, 82%); m.p. 72-74° C [Lit. Can. J. Chem. 1985 63, 2787; m.p. 75-76° C. Sublimation of such a sample at 100°/0.2 mm gave white crystals, m.p. 72-74° C.

Provenance & Evidence