The main synthesis methods of sulfamic acids are sulfonation of alkyl amine with sulfur trioxide complex R3N·SO3 <58JOC1133> and treatment of amine with chlorsulfonic acid <44JOC89, B-91Mi 206-01>. For example, sulfamic acid of 5' -amino-5 '-deoxyadenosine is prepared by treating 5' -amino-5' -deoxyadenosine with Me3N·SO3 in anhydrous methanol (Equation (44)) <78JMC704>. Many other methods of preparing sulfamic acid have been reported, such as the treatment of isocyanates or carbamate with fuming sulfuric acid <76JOC4028> and the reaction of hydroxylamine or amine N-oxide with sulfur dioxide <72CJC3502>. Catechol sulfate reacts with amines to produce 2- (hydroxyphenyl) sulfamate, which can be hydrolyzed to produce potassium sulfamate <82USP4290975>. A large amount of sodium hET -NHSO3−Na+ has been prepared for testing as an artificial sweetener <B-91MI 206-01>. Interestingly, although not part of this chapter, n-acylsulfamate monocyclic lactam antibiotics are β -lactam with a sulfamate portion on β -lactam nitrogen and are usually prepared using a sulfur trioxide complex.
Chemical burns occur when living tissue comes into contact with corrosive chemicals. While the majority of chemical burns are to the skin, many can also be caused by eye contact, ingestion and inhalation of corrosive substances. It is important to distinguish between chemical stimulation and combustion. Chemical irritants can cause a reversible reaction, including swelling, itching and burning. However, these effects are short-lived and the skin returns to its normal state when the irritant is removed. Chemical burns, on the other hand, are irreversible and can cause permanent damage.
Substances that cause chemical burns include acids, bases, solvents, oxidizers and reducing agents. Most chemical burns, including those caused by acid, denature proteins on contact and produce coagulative necrosis. Alkali causes tissue liquefaction by denaturation of protein and saponification of fat, resulting in liquefaction necrosis. In acid burns, tissue penetration is limited by clotting, limiting damage. Alkali burns that do not cause clotting continue into tissues [39]. This phenomenon makes alkali burns potentially more dangerous because they do not always produce symptoms immediately but develop gradually over time, producing extensive tissue destruction. Therefore, alkali burns are also called progressive burns. It should be noted that hydrofluoric acid is unique among acids in that it produces liquefaction necrosis in the same way as bases, making it probably the most dangerous acid for skin contact.
