Half ester, of malonic acid

Catalytic reduction of the nitrile 79 in the presence of semicarbazide affords initially the semicarbazone of 80. Hydrolysis-interchange, for example in the presence of pyruvic acid, gives the aldehyde 80. Condensation with the half ester of malonic acid leads to the acrylic ester 81 the double bond is then removed by means of catalytic reduction (82). Base catalyzed reaction of the... 

One such compound, bropirimine (112), is described as an agent which has both antineo-plastic and antiviral activity. The first step in the preparation involves formation of the dianion 108 from the half ester of malonic acid by treatment with butyllithium. Acylation of the anion with benzoyl chloride proceeds at the more nucleophilic carbon anion to give 109. This tricarbonyl compound decarboxylates on acidification to give the beta ketoester 110. Condensation with guanidine leads to the pyrimidone 111. Bromination with N-bromosuccinimide gives bropirimine (112) [24]. 

Half ester, of malonic acid, 37, 34 Heating tape, 37, 4, 68 Heat transfer salt, 37, 49... 

The half esters of malonic acid (105) yield Q ,Q -dinitroesters (106) on nitration-decarboxylation with nitric acid, although yields are often poor. Treatment of these Q ,Q -dinitroesters with hydrazine hydrate or alkali metal hydroxides yields the corresponding m-dinitroalkanes. ... 

Diphenyl Malonate and Diphenyl Oxalate. Above 200°C, the half ester of malonic acid decomposes to carbon dioxide and an ester of acetic acid, and the half ester of oxalic acid decomposes to carbon dioxide and an ester of formic acid. Diphenyl malonate and diphenyl oxalate are chain extenders that decrease the terminal PET COOH content by these decomposition reactions. 

Pentadienoates.1 Half esters of malonic acid react with a,(3-enals in pyridine containing dimethylaminopyridine to form these diunsaturated esters, with generally high (2E)-selectivity. 

The oximino group in (149) can be introduced through nitrosation on carbon if there is an active hydrogen at that carbon atom. For example, nitrosation of the acylamino half ester of malonic acid gives an intermediate (163) that can isomerize to an oxime (164) and then cyclize to a 3-ethoxycarbonyloxadiazole (165). 

A half-ester of malonic acid such as 111, prepared in 70% yield by partial saponification of the di-ester, is oxidized by lead tetraacetate in benzene at 50° to the a-acetoxy derivative V, which loses carbon dioxide at 200° to give the a-acetoxy ester VI. Yields are in the range 35-80%. That the half-esters are oxidized much... 

Dimethyl-2-phenylperhydro-l,4-oxazepine-5,7-dione W was prepared from the half ester of malonic acid and- -ephedrine and syntheses of various optically active carboxylic acids starting from this chiral oxazepine were investigated. 

Kozeschkow and Alexandrow (146) obtained a-plumbylcarboxylic acid esters starting from plumbyl half-esters of malonic acid which de-carboxylate at 180° C. 

Triphenylplumbyl half-esters of malonic acid can be decarboxylated, as mentioned in Section C, with the formation of a new Pb—C bond. Willemsens and van der Kerk (274) and Davies et al, (45) have extended this procedure to other triphenylplumbyl esters of carboxylic acids, an example being phenylpropiolic acid. 

Both aldehydes or ketones can be condensed with malonate derivatives, but ammonia can be used as a base rather than pyridine. Reaction of butanal with ammonia in the presence of the half-ester of malonic acid, for example, gave ethyl... 

An apparently very simple synthesis of the bis-lactone avenadolide (75) (4, 119) involves a condensation between a suitable a-chloro-aldehyde and the half-ester of malonic acid in a two-phase system (C6H6-H2O) containing Bu"4NBr (Scheme 9). Presumably the first step proceeds via esterification of... 

Another attractive synthesis of PG s published this year starts from ( —)-5 -malic acid (67). The acid is first converted into the corresponding acid chloride (68), which by reaction with the half ester of malonic acid leads to 1,4-dione (69). Aldol cyclization of the 1,4-dione at pH 8.5 produces next the five-ring diester (70), in... 

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