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Abstract

Methyl 2-cyano-3-(4-bromo-5-R-X-2-furyl)-2-propenenitriles and 2-propenoates were prepared from 2-cyano-3-(4,5-dibromo-2-furyl)-2-propenenitrile and methyl 2-cyano-3-(4,5-dibromo-2-furyl)-2-propenoate and the respective nucleophiles R-XNa (X = S, R = C₆H₅, 2-benzimidazolyl, 2-benzothiazolyl, 2-pyrimidinyl, and X = SO₂, R = C₆H₅). The same products also originate by condensation of 4-bromo-5-R-X-2-furaldehydes with malononitrile or methyl cyano acetate under catalysis of alcoholates. Bis(3-bromo-5-formyl-2,2'-furyl) sulfide and bis(5-formyl-2,2'-furyl) sulfide were prepared from 4-X-5-bromo-2-furaldehydes (X = H, Br) with sodium sulfide. 4-Bromo-5-X-2-furaldehydes (X = H, Br) react with sodium hydrogen selenide to give bis-(3-bromo-5-formyl-2,2'-furyl)- or bis(5-formyl-2,2'-furyl) selenides. 2-Cyano-3-(4-bromo-5-amino-2-furyl)-2-propenenitrile and methyl 2-cyano-3-(4-bromo-5-amino-2-furyl)-2-propenoate were synthesized from the corresponding 4,5-dibromo derivatives, sodium azide and malononitrile. All compounds are characterized by UV spectral data; kinetics of nucleophilic substitution reactions with piperidine is presented, as well.