Reaction of 5-substituted 4,6-dichloro-2-aminopyrimidines with oxalyl chloride

The reaction of 5-substituted 4,6-dichloro-2-aminopyrimidines with oxalyl chloride gives 2-isocyanatopyrimidines, the structures of which were proved by chemical means and the IR, PMR, and ³⁵Cl nuclear quadrupole resonance spectra. The intermediate pyrimidinyloxamic acid chlorides were not isolated; this is evidently explained by the low basicities of 2-amino-pyrimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1248–1251, September, 1977.     

Electron beam stimulated chemical reaction in solids

Use of electron beams allows to obtain new effects in high temperature chemistry of solid state. A stimulated influence of irradiation at comparable temperature conditions may be a subject of technological interest taking into account that increase of reaction rate can reach significant values.     

Correlations between parameters of melting and conductivity of solid lonic compounds

Analysis of the literature data allows one to correlate the melting parameters and the activation enthalpy H₀ of the charge carrier formation in an ionic crystal. The melting enthalpy H_m and H₀ values are connected by the basic relation H₀ = 9.2 H_m. The well-known Barr-Lidiard relation is shown to be a particular case of this basic relation. It is demonstrated that the conductivity jump at the melting temperature of an ionic crystal may be predicted from the melting entropy. Correlations of the form mentioned above may be useful in predicting the conductivity values of ionic crystals as well as in looking for new types of superionic conductors.     

Implementation of ISO/IEC 17025 Standard for the accreditation of analytical laboratories in Russia

The history since 1992 and the current state of affairs of the Russian Accreditation system for analytical laboratories are described. Some national characteristics of the implementation of the ISO/IEC 17025 Standard in Russia are considered. The elucidation of some ISO/IEC 17025 Standard prepositions is presented to facilitate implementation of the Standard by accreditation bodies and analytical laboratories claiming accreditation.