Optical resolution of racemic 5-oxo-1-phenyl-pyrazolidine-3-carboxylic acid 2 with L-amino acid methyl ester via the diastereomers formation was investigated. Treatment of racemic 5-oxo-1-phenylpyrazolidine-3-carboxylic acid 2 with L-valine methyl ester gave diastereomers with a total yield of 86%. The diastereomeric dipeptides can be easily separated by flash column chromatography. Acidic clea...

Ethyl 2,3-diendo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylate ((±)-1) was resolved with O,O'-dibenzoyltartaric acid via diastereomeric salt formation. The efficient synthesis of the enantiomers of 2,3-diendo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid ((+)-7 and (-)-7), 3-endo-aminobicyclo[2.2.2]oct-5-ene-2-exo-carboxylic acid ((+)-5 and (-)-5), cis- and trans-3-aminobicyclo[2.2.2]octane-2...

The condensation of substituted pyrazine-2-carboxylic acid chlorides with ring-substituted anilines yielded five substituted pyrazine-2-carboxylic acid amides. Thesynthesis, and analytical, lipophilicity and biological data of the newly synthesizedcompounds are presented in this paper. The photosynthesis inhibition, antialgal activityand the effect of a series of pyrazine derivatives as abiotic...

Rapid and highly efficient synthesis of 2- or 2,5-substituted 1,3,4-oxadiazoles by the condensation of aryl carboxylic acid hydrazides and orthoesters can be achieved under microwave irradiation using an unmodified commercial over in unsealed vessels.

The production of carboxylic acids by partial wet oxidation of alkali lignin at elevated temperatures and pressures was studied experimentally. Two different heteropoly acids, phosphotungstic acid (H₃PW12O40) and phosphomolybdic acid (H₃PMo12O40), were used to catalyze the oxidation of lignin under hydrothermal conditions. Factors influencing the total yield of carboxylic acids formed during th...