Studies on pyrazine derivatives. Part XIII. synthesis and tuberculostatic activity of some 6-alkyl-amino- and 6-dialkylhydrazinopyrazine-2-carboxylic acids derivatives.

6-RNH- and 6-R2NNH-pyrazine-2-carbothioamides 1--3, 5, 6, 9 and 14 were obtained from 2-cyano-6-chloropyrazine. In the in vitro screening the thioamides were active against Myc. tuber.

Reactions of cyanomethylbenzimidazoles. Part III. Reaction of cyanomethylbenzimidazoles with isocyanates and isothiocyanates.

In the reaction of 2-cyanomethylbenzmidazole and their 1- and 5-methyl derivatives with aromatic isocyanates and isothiocyanates, 23 N-arylamides resp. thioamides of benzimidazolyl-2-alpha-cyanoacetic acid were obtained. The structure of the newly compounds (Table 1) was confirmed by NMR and IR spectra.

Investigations of pyrazine derivatives. Part IV. Synthesis and tuberculostatic activity of some 6-alkoxypyrazine-2-carboxylic acids.

By alcoholysis of 2-cyjano-6-chloropyrazine corresponding 6-alkoxypyrazine-2-imidoesters (1,6,11,16) were formed, which were then transformed in esters and amides of 6-alkoxypyrazine-2-carboxylic acids. Some of these compounds show a weak tuberculostatic activity.

Synthesis of some 2-aminonicotinic acid derivatives.

The nucleophilic exchange of chlorine atom in 2-chloro-3-cyanopyridine with morpholine, piperidine and pyrrolidine was carried out. Acids, amides, thioamides, esters and hydrazides were derived from the obtained compounds (Fig. 1).

Reactions of cyanomethylbenzimidazoles. Part II. Reaction of cyanomethylbenzimidazoles with aldehydes methylketones and nitroso compounds.

Position of CH2CN group in the benzimidazole system determines the activity of hydrogen atoms of CH2 group in condensation reactions. Some of the obtained compounds show high tuberculostatic activity.

[Nocardia pellegrini: III. An attempt of phage typing(author's transl)].

The typing of Nocardia pellegrini with different Nocardia-phages was studied. The investigation included 25 Nocardia pellegrini strains, 19 strains of different Nocardia species and also strains of different species of mycobacteria. It could be stated that phages typical for Nocardia pellegrini were also active against other fast fragmentating Nocardia species, such as Nocardia corallina or Nocardia rubra.