α‐Substituierte Dopacetamide als Hemmer der Catechol‐O‐methyl‐transferase und der enzymatischen. Hydroxylierung aromatischer Aminosäuren. In den Catecholamin‐Metabolismus eingreifende Substanzen. 2. Mitteilung

A series of α‐substituted 3,4‐dihydroxyphenylacetamides (dopacetamides) was synthesized and screened for catechol‐O‐methyl‐transferase (COMT) inhibiting activity. The α‐propyl‐3,4‐dihydroxyphenylacetamide (H 22/54) was found to be most potent. 4‐Tropolone‐acetamide was also shown to be a potent inhibitor of COMT. The dopacetamides also block the biosynthesis of catecholamines and 5‐hydroxytryplamine, most probably by inhibiting enzymatic hydroxylation of L ‐phenylalanine, L ‐tyrosine and L ‐tryptophan.