Views: 2 Author: Site Editor Publish Time: 2023-04-07 Origin: Site
Aniline is mainly used in the preparation of methylenedianiline and related compounds by condensation with formaldehyde. Condensation of diamines with phosgene yields methylene diphenyl diisocyanate, a precursor to polyurethane polymers.Other uses include rubber processing chemicals (9%), herbicides (2%), and dyes and pigments (2%).As an additive to rubber, aniline derivatives such as phenylenediamine and diphenylamine are antioxidants.An example of a drug prepared from aniline is paracetamol (paracetamol,Tylenol). The main use of aniline in the dye industry is as a precursor for indigo (the blue color of blue jeans).
In 1856,von Hoffmann's student William Henry Perkin discovered fuchsia while attempting to synthesize quinine and put it into industry to produce the first commercially synthesized dye.Other aniline dyes followed, such as magenta, safranin, and dihydronaphthalene.When it comes to fuchsia, aniline is expensive.Shortly thereafter, applying the method reported by Antoine Béchamp in 1854,it was prepared "by the ton".The Béchamp reduction contributed to the development of a large-scale dye industry in Germany. Today, BASF, whose name was originally Badische Anilin- und Soda-Fabrik (English: Baden Aniline and Soda Factory), is now the largest supplier of chemicals, echoing the tradition of the synthetic dyes industry, which was established with aniline dyes and passed Related azo dye extension dyes.The first azo dye was aniline yellow.
In the late 1800s, aniline derivatives such as acetanilide and phenacetin emerged as pain relievers whose heart-depressing side effects were usually offset by caffeine.In the first decade of the 20th century, Paul Ehrlich failed in his attempts to modify synthetic dyes to treat African sleeping sickness the chemotherapy he created for his magic bullet method and turned to modify Béchamp's atoxyl, the first organic arsenic drug, and fortuitously obtained a drug for syphilis salvarsan the first successful chemotherapeutic drug. Salvarsan's target organism has not been identified as a bacterium and is still considered a parasite, medical bacteriologists considered bacteria insensitive to chemotherapy and therefore ignored Alexander Fleming's 1928 report on the effects of penicillin.
In 1932, Bayer sought medical applications for its dyes.Gerhard Domagk identifies a red azo dye as an antibacterial agent, which was introduced in 1935 as the first antibacterial drug, Prandoxil, which was soon discovered as a prodrug at the Pasteur Institute which degrades in vivo to sulfonamides colorless intermediates of many highly fast azo dyes has been synthesized with an expired patent by researcher Paul Gelmo in Vienna in 1908 for his doctoral research.By the 1940s, more than 500 related sulfa drugs were produced.Drugs were in high demand, and these first miracle drugs, widely effective chemotherapy, boosted the US pharmaceutical industry. In 1939 at Oxford University, in search of an alternative to sulfonamides,Howard Florey developed Fleming's penicillin into penicillin G, the first systemic antibiotic drug. For topical use only. ) After World War II, Cornelius P. Rhoads introduced chemotherapy into cancer treatment.
Some early American rockets, such as the Aerobee and WAC Corporal, used a mixture of aniline and furfuryl alcohol as fuel, with nitric acid as the oxidizer.The combination is pyrophoric and ignites when the fuel and oxidizer come into contact.It is also dense and can be stored for a long time. Aniline was later replaced by hydrazine.
Toxicology and testing
Aniline is toxic by inhalation of vapors, ingestion or skin absorption.Due to the limited and conflicting data available, IARC classified it in Group 3 (cannot be classified as carcinogenic to humans).Early manufacture of anilines led to increased rates of bladder cancer, but these effects are now attributed to naphthylamines, not anilines.Aniline is considered one of the possible causes of forest dieback.
There are many methods for detecting aniline.
Oxidative DNA damage
Exposure to aniline in rats elicited toxic responses in the spleen, including tumorigenic responses.After exposure of rats to aniline in drinking water, oxidative DNA damage was significantly increased in the spleen, and a 2.8-fold increase in 8-hydroxy-2'-deoxyguanosine (8-OHdG) was detected in its DNA.Although the base excision repair pathway is also activated, it is not active enough to prevent the accumulation of 8-OHdG. Accumulation of oxidative DNA damage in the spleen after exposure to aniline may increase mutagenic events in tumorigenesis.