Naphthalene is a hydrocarbon produced by the distillation of coal tar and is an aromatic white crystalline substance. Naphthalene is the most abundant component in coal tar. It is used as an insect repellant and insect fumigant. The compound is used in the manufacture of celluloid, dyes, hydrogenated naphthalenes, oil fumes, smokeless powders and synthetic resins.
Over the past few years, many pyrazole fused-ring systems, especially with applications in medicinal chemistry, have been published. These include general structures such as pyrazoline, pyrazoline, pyrazoquinoline, pyrazoloisoquinoline, pyrazoline, pyrazolopyrazine, pyrazolopyrazine, pyranopyrazole, pyrano Pyrazoles, pyrazolotriazines and pyrazole fused phosphorus rings.