The reactions of the methoxybenzylidene derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione and their saturated analogs with potassium hydroxide in methanol, ammonia, and hydrazine hydrate were realized. The 1,2-bis(methoxybenzylidene)hydrazines, amides, and hydrazides of methoxybenzylidenemalonic acid, suitable for use as structural blocks in the synthesis of various structures based on them, were prepared and characterized.The methoxyphenyl substituent is a structural fragment of a large number of pharmaceutical preparations, the best known of which are drugs with a stimulating action on the cardiovascular system [1, 2] and neurotropic activity [3].As starting materials containing the above-mentioned fragment for the synthesis of new compounds, unknown in the literature, we chose the methoxybenzylidene derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione 3 and their saturated analogs 4. Compounds 3 are the products from the condensation of methoxy-substituted benzaldehydes 1 with 2,2-dimethyl-1,3-dioxane-4,6-dione (isopropylidenemalonate, Meldrum's acid) (2).Methods for the production of the 2,5-(3a), 2,4-(3b), and 3,4,5-(3c) methoxybenzylidene derivatives are known in the literature [4], and the 2,3,4-(3c) and 3,4,5-(3d) methoxy derivatives were obtained by an analogous procedure.The hydrogenation of compounds 3 was conducted with sodium borohydride in methanol at room temperature.In view of the fact that the 1,3-dioxane ring in isopropylidenemalonates readily undergoes decomposition with ring opening in reactions with nucleophilic reagents [5-7] we realized the reactions of compounds 3 and 4 with potassium hydroxide in methanol, ammonia (donors of ammonia: ammonium hydroxide and hexamethyldisilazane), and hydrazine hydrate.
