1. Aminotrimethylquinone has been synthesized. 2. This quinone reacts with sodiomalonic ester to form 3-carbethoxy-5,8dimethyl-6-hydroxy-7-aminocoumarin (II = B) by attack of the enolate anion at the methyl group of the quinone para to the amino group, demonstrating the strong resonance effect (electron release) of the amino group in this quinone.3. The chemical properties of the aminocoumarin have been investigated and several derivatives of it have been prepared. 4. The structure of the aminocoumarin (II = B) has been proved by an independent synthesis starting with p-xylohydroquinone. Minneapolis 14, Minnesota