A. McKillop

Abstract: A new and reliable synthesis of diethyl β-ketoadipate (Ia) is described, in which the ethoxymagnesio derivative of ethyl t-butyl malonate is condensed with β-carbethoxypropionyl chloride to the triester (VI, R = Et), which is decomposed by refluxing under vacuum in the presence of added acid. Distillation gives pure diethyl β-ketoadipate (Ia). Previously described procedures for the preparation of Ia are shown to give impure products.

Abstract: The furan dicarboxylic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (5-propyl FPA) accumulates in the plasma of patients with chronic renal failure and is a major contributor to the drug binding defect of uraemic plasma. This acid has also been implicated in several other aspects of the uraemic syndrome: anaemia, irregularities of thyroid function, neurological symptoms and inhibition of active tubular secretion. The acid is not commercially available and its synthesis, starting with Meldrum's acid and methyl succinyl chloride, is described. The pKa values were measured by titration and values of 3.2 and 3.6 respectively were assigned to the carboxylic acid groups attached directly to the ring at position 3 and at position 2 (on the side-chain). The partition coefficient (log P) between hydrochloric acid and octanol was 1.2 and the distribution coefficient (log D; octanol-phosphate buffer pH 7.4) was -0.59. The pKa values and the degree of hydrophobic character of 5-propyl FPA are consistent with those of other protein-bound acids which undergo active tubular secretion by the kidney and this substance may serve as an endogenous marker for the effects of drugs and disease on this process.

Abstract: Monoethyl malonate (1) and tert-butyl alcohol are esterified by catalysis with dicyclohexylcarbodiimide and 4-dimethylaminopyridine to yield ethyl t-butyl malonate (2). The ethoxymagnesio derivative (3) of the ester is condensed with b-carbomethoxypropionyl chloride to give the triester (4), which is decomposed by heating under vacuum in the presence of b-naphthalensulfonic acid to give ethyl methyl β-ketoadipate (5). Compound 5 is reacted with hydrogen cyanide,followed by hydrolysis of the cyanohydrin to give the free acid (6). Compound 6 is converted to homocitrate (7) by the use of an improved procedure.

Abstract: The review describes the flourishing synthesis and brief structure-anti-HIV-1 activity relationships of 6-(arylmethyl)pyrimidin-4(3H)-one derivatives.