Formation of arylacetic acids, arylacetamides, and aryldihydropyrroles from aromatic aldehydes

Abstract

Furfuraldehyde, 4-hydroxybenzaldehyde, and 4-hydroxy-3-methoxybenzaldehyde were converted into 2-furylacetic, 4-hydroxyphenylacetic and 4-hydroxy-3-meth-oxyphenylacetic acids respectively on reaction with glyoxal bisulphite and cyanide in alkaline solution. Under the same reaction conditions, 2-hydroxybenzaldehyde yielded 2-hydroxyphenylacetic acid and 3-(2'-hydroxypheny1)-2H-chromen-2-one. When ammonia was present in the reaction mixture, furfuraldehyde and 4-hydroxy-benzaldehyde formed 2-furylacetamide and 4-hydroxyphenylacetamide respectively. Alternatively, in the presence of methylamine, furfuraldehyde yielded 5-(2'-furyl)-2-imino-1-methyl-2, 5-dihydropyrrole-3, 4-diol and benzaldehyde ..