Malonamic acid esters

Acoxynitrones a-Acylperoxynitriles Carbamylketeneacetals Malonamic acid esters... 

Chemical Name Malonamic acid, N-(2-carboxy-3,3-dimethyl-7-oxo-4-thia-l-azabicyclo(3.2.0)hept-6-yl)-2-phenyl-, 1-phenyl ester monosodium salt... 

Diacids.—Succinic acid derivatives can be obtained in good yields by coupling lithium a-lithiocarboxylates (or ester enolates) with lithium a-halocarboxylates, or a-halo-esters/ Carboxylic acid dianions also react with isocyanates and iso thiocyanates to give malonamic acids (13 X = O) and 3-thiomalonamic acids (13 X = S), respectively/ A route to c/5-cyclobutane-l,2-dicarboxylic acids (16), which could be of some generality, consists of photocyclization of acryl-imides (14) to maleimides (15) and hydrolysis/ Yields of (15), as judged by n.m.r. spectra, are between 45 and 82%. 

Ar-(2-Pyridyl)malonamates 115, obtained in the reaction of 2-aminopyri-dines and malonic acid half-ester chloride, were cyclized in a mixture of phosphoryl chloride-polyphosphoric acid at 130°C for 2-5.5 hours to give 2-chloro-4//-pyrido[ 1,2-a]pyrimidin-4-ones 116 (84S152). 

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