4-Ethynylbenzoic acid → methyl 5-(4-ethynylbenzoyl)-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate

Beteiligte Stoffe

Reaktionsschritte

A solution of methyl 1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate (2.50 g, 0.015 mole) in dry xylene (100 ml) containing the acid chloride of 4-ethynylbenzoic acid [4.40 g, 0.026 mole; L. E. Salisbury, J. Org. Chem., 43, 4987 (1978)] was heated at reflux temperature for 12 hours. The solvent was removed in vacuo and the residue was purified by chromatography on alumina (200 g) using hexane/ethyl acetate (95:5) as the eluting solvent to give methyl 5-(4-ethynylbenzoyl)-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate, m.p. 113°-114° C.

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