Keywords: aromatic acid halides, hydrazide, hydrazine hydrate, hydrazinolysis, X-ray analysis.The studies [1,2] demonstrated the possibility of a stepwise hydrazinolysis of the ester groups in diethyl 2,6-dimethyl-3,5-pyridinedicarboxylate with subsequent formation of 3-ethoxycarbonyl-2,6-dimethyl-5-pyridine-carboxylic acid hydrazide (1) and 2,6-dimethyl-3,5-dipyridinedicarboxylic acid dihydrazide (2) and then the corresponding hydrazones using aromatic aldehydes. It was found that the free ester group in the case of the hydrazones obtained from the monohydrazide 1 does not participate in the hydrazinolysis reaction.With the aim of investigating the chemical properties of the hydrazides 1 and 2 we have studied their acylation reaction with the aromatic acid halides 3a-h. This reaction occurs under base catalysis conditions using dry, refluxing acetonitrile. The choice of solvent and the temperature conditions are limited by the solubility of the hydrazides 1, 2 in organic solvents.The 3,5-pyridinedicarboxylic acid N-aroyl hydrazides 4, 5a-h formed in the reaction are neutralized using aqueous alcoholic sodium bicarbonate solution to give the corresponding bases 6, 7a-h (Tables 1-3). As is evident from the Table the most difficulty occurs in the reaction with 2-methoxybenzoyl chloride and this is evidently linked both with the lower electrophilicity of the reagent and with the steric hindrance generated by the ortho-methoxy group.The N-aroyl hydrazides 6, 7a-h are quite stable to acid and base hydrolysis but this occurs to give 2,6-dimethyl-3,5-pyridinedicarboxylic acid by refluxing for 6-10 h in 15% hydrochloric acid, virtually the same time being needed for the complete hydrolysis using a 2N aqueous alcohol solution of potassium hydroxide under reflux.The ester group of the monohydrazide 1 readily takes part in a hydrazinolysis reaction to give the dihydrazide 2 [1]. We were interested in the possible hydrazinolysis of the ester group in the obtained N-aroyl hydrazides 6a-h. It was found that prolonged reflux of both the bases 6a,b,e,f,h and the hydrochlorides __________________________________________________________________________________________

5-(2,4,6-Trinitrophenyl)furfural.-Furfural, activated by formation of the corresponding dimethylhydrazone (I), smoothly undergoes reaction with picryl chloride to furnish, after deprotection of the formyl group, the title 5arylfurfural (IV) which is capable of azomethine (VI) formation. -(IVONIN, S. P.; ANISHCHENKO, A. A.; VOEVUDSKY, M. V.; DMITRIKOVA, L. V.; Khim.

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Substituted Ureas Based on 2,6-Dimethyl-3,5-pyridinedicarboxylic Acid Azides.-Azides (I) and (VII) are converted into the corresponding isocyanate intermediates by Curtius rearrangement which further react with ammonia, primary, secondary amines to give mono-, di-, and trisubstituted ureas. In the presence of imidazole, symmetrical urea (VI) is formed. -(NESTEROVA, E. Y.; PUGACHEVA, A. S.; VOEVUDSKY*, M. V.; Chem. Heterocycl.