The electrophilic substitution reactions of 2-aminotropone (I), 2-methylaminotropone (II), and 2-dimethylaminotropone (III) were investigated. The structure of the products was proved by hydrolysis to lead to known tropolone derivatives. By the nitrosation of II, N-nitroso-2- methylaminotropone was obtained in a good yield; this compound is a new type of active troponoid compound. The substitution reactions of III gave tropolone derivatives, ...