Formamidines aminomethylenemalonates

When a mixture of 3,4-methylenedioxyaniline, ethyl formimidate, and diethyl malonate was reacted at 110-I20°C for 6 hr, 30% of diethyl malonate and 19% of 3,4-methylenedioxyaniline were recovered. In addition, 18% of /V-(3,4-methylenedioxphenyl)aminomethylenemalonate (258), 11% of formamidine (259), and 7% of /V-(3,4-methylenedioxyphenyl)amino-methylenemalonamate (260) were isolated from the reaction mixture by means of column chromatography (74MI2). 

AM3-Chlorophenyl)aminomethylenemalonate (250) was obtained in pure form in 94% yield when /V,A, -bis(3-chlorophenyl)formamidine (248) (1 mol), diethyl malonate (I mol), and ethyl orthoformate (1.2 mol) were reacted for 20 hr at 126°C, the ethanol evolved being continuously distilled off. More diethyl malonate (1 mol) was then added to the half-converted reaction mixture, and the reaction mixture was stirred at 126°C for 48 hr (65MIP1 66JOC4003). Under these conditions, the formation of N- 3-chlorophenyl)aminomethylenemalonamate (252, R = 3-C1) could be excluded because the 3-chloroaniline formed in the reaction of amidine and malonate was simultaneously converted to amidine by ethyl orthoformate. 

N-(6-Methyl-2-pyridyl)aminomethylenemalonate (306) was prepared in 94% yield in the reaction of N,N -bis(6-methyl-2-pyridyl)formamidine and diethyl malonate in the presence of ethyl orthoformate at I50°C for 1 hr, the ethanol formed being removed [74JAP(K) 101380]. 

N,)V -Bis(cyclohexylaminocarbonyl)formamidine (310) was reacted with diethyl malonate in ethanol at 70°C for 60 hr to give N-(cyclohexylami-nocarbonyl)aminomethylenemalonate (311, R = Et) in 24% yield (53-JA671). The similar reaction of malonic acid at room temperature for 3-4 min afforded (cyclohexylaminocarbonyl)aminomethylenemalonic acid (311, R = H) in 65% yield. When bis(cyclohexylaminocarbonyl)for-mamidine (310) was reacted with 1 1 molar mixture of diethyl malonate and malonic acid in ethanol at 70°C for 5 min, only malonic acid (311, R = H) was obtained, in 76% yield. 

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See also in sourсe #XX -- [ ]

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