From Nitriles and Dialkyl Malonates

Dimethyl malonate was reacted with nitriles in boiling 1,2-dichloro-ethane in the presence of SnCl4 for 26-50 min to give white crystalline products, which were treated with aqueous sodium carbonate to afford dimethyl aminomethylenemalonates (312, R = R1 = Me, R2 = Me, Et, Ph, CH=CHPh, CH=CHMe) in 17-57% yields (85TL2603). Earlier di- 

Under the previous conditions, diethyl (amino)phenylmethylenemalo-nate (313) was also obtained in 35% yield in the reaction of diethyl bromo-malonate and benzonitrile (85TL2603). 

The reaction of 3-nitrobenzonitrile (R2 = 3-N02Ph) and dimethyl malo-nate in the presence of SnCl4 in boiling 1,2-dichloroethane for 1 hr gave dimethyl amino(3-nitrophenyl)methylenemalonate (312, R = R1 = Me R2 = 3-N02Ph, R1 = 3-N02C6H4) in 66% yield (87EUP228845). 

The reactions of ethyl cyanoformate and dialkyl malonates in the presence of zinc chloride and triethylamine, or in the presence of TiCl4 or SnCl4 in methylene chloride at reflux temperature for 3 hr, or at room temperature overnight, gave amino(alkoxycarbonyl)methylenemalonates (314, R1 = Et) in good yields [79TL2525 81JAP(K)71050], 

Amino(alkoxycarbonyl)methylenemalonates (314) were also prepared in good yields in the reactions of dialkyl cyanoformate and bromo- or chloromalonates in the presence of SnCl2 or TiCl3 in benzene, or in the presence of zinc activated by copper in THF, [81JAP(K)71049, 81JAP(K)87542]. 

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