1,5-Naphthyridines and their n-oxides III. Synthesis and biological activity of some mono- and disubstituted 1,5-naphthyridines and their n-oxides
In order to search for biologically active compounds in the 1,5-naphthyridine series, we synthesized 2-mercaptoand 2-(4'-aminobenzenesulfonamido)-l,5naphthyridines and some of their 6-substituted derivatives. 2-(4'-Aminobenzenesulfonamido)-l,5-naphthyridine (I) was obtained by reaction of 2-amino-l,5naphthyridine with 4-carbomethoxyaminobenzenesulfonyl chloride in pyridine with subsequent saponification of the carbomethoxy group in the resulting 2-(4'carbomethoxyaminobenzenesulfonamido)-l,5-naphthyridine (II).
Tautomerism in side-chain derivatives of n-heterocycles
Abstract NMR and UV spectra of some α (ψ)cyano-, carbethoxy-, and acylmethyl derivatives of 2-oxo-1,2-dihydroquinoxaline, 2-oxo-1,2-dihydro-6,7-benzoquinoxaline, 3,4-dihydro-1,4,2H-benzoxazone, quinaxoline, and quinoline, were recorded in chloroform, dimethyl sulfoxide, and trifluoro- acetic acid. The results indicate the existence of tautomeric equilibria, with noticeable contribution of the enaminic structures B or D, depending on the solvent and the nature of the heterocycle. Relationhips between some NMR parameters and tautomeric structures were observed.
Achievements and contradictions of the Peruvian agrarian reform
Different paths of transition to capitalist agriculture, as well as different types of agrarian reform, can be distinguished. The Peruvian agrarian reform is analysed within this context and evaluated in terms of its contribution to rural development. The Peruvian case underlines the importance of understanding the rationality of the pre‐existent agrarian system for a successful restructuring of the agrarian economy and society. The contradictions which arose between the State's model and the peasants’ model of agrarian reform, as well as those between different types of peasants, are discussed. Peru's experience is also a reminder that a land reform is not a sufficient condition for rural development unless accompanied by proper price, marketing, credit and investment policies.