Synthesis and Antiplatelet, Antiinflammatory and Antiallergic Activities of 2,3-Disubstituted 1,4-Naphthoquinones.

Modification of 2-acetamido-3-chloro-1, 4-naphthoquinone, which has potent antiplatelet, antiallergic and antiinflammatory activities, led to a series of 2, 3-disubstituted 1, 4-naphthoquinones. Some of these compounds showed significant antiplatelet, antiallergic and antiinflammatory activities. Among them, 2-methoxy-3-chloro-1, 4-naphthoquinone (15) and 2-ethoxy-3-chloro-1, 4-naphthouinone (17) exhibited potent inhibitory effects on neutrophil and mast cell degranulation. 2-Methoxy-1, 4-naphthoquinone (20) and 2-ethoxy-1, 4-naphthoquinone (21) exhibited potent inhibitory effect on neutrophil superoxide formation. These four compounds were thus selected for further evaluation