A. Kost, I. I. Grandberg
1966
Citations
1
Influential Citations
155
Citations
Quality indicators
Journal
Advances in Heterocyclic Chemistry
Abstract
Publisher Summary This chapter discusses the use of pyrazole as antioxidants in motor fuels, medicine, and development of cine-film. Besides the traditional interest in pyrazole derivatives which have been the basis of numerous dyes and drugs, a number of pyrazole anesthetics have appeared. Recent studies have established that pyrazolines are intermediates in the synthesis of cyclopropanes; they act as effective chemical bleaching agents, and as a constituent of luminescent and fluorescent substances. Pyrazoles are stable compounds with relatively high boiling points. It is a colorless compound with a peculiarly penetrating sweetish smell. The introduction of substituents in the 3-, 4-, and 5-positions causes an increase in the boiling point, which is expected with increased molecular weight, but the boiling point falls sharply with substitution in the 1-position. Similarly, 1-substituted pyrazoles melt at temperatures significantly lower than the corresponding compounds with free N-H groups. Both of these anomalies are due to the particularly strong association of pyrazoles unsubstituted in position 1, as proved by cryoscopic determination, spectral studies, dipole moment measurement, and infrared spectroscopy.