Salicylic acid the OH group is "ortho" to the carboxyl group. It is also known as 2-hydroxybenzoic acid. It is poorly soluble in water (2 g/L at 20 °C). Aspirin (acetylsalicylic acid or ASA) can be prepared by the esterification of the phenolic hydroxyl group of salicylic acid with the acetyl group from acetic anhydride or acetyl chloride. Salicylic acid can also be prepared using the Kolbe-Schmitt reaction. Salicylic acid is used as a food preservative, a bactericidal and an antiseptic. Sodium salicylate is a useful phosphor in the vacuum ultraviolet spectral range, with nearly flat quantum efficiency for wavelengths between 10
Tetrolic acid Tetrolic acid Tetrolic acid (2-butynoic acid) is a short-chain unsaturated carboxylic acid, described by the formula CH-C≡C-COH. Salts and esters of tetrolic acid are known as tetrolates. The first reported synthesis of tetrolic acid is believed to be by German chemist Johann Georg Anton Geuther in 1871 as part of his work investigating the derivatives of ethyl acetoacetate. Tetrolic acid is manufactured on a commercial scale by treatment of propyne with a strong base (to form an acetylide), followed by carbon dioxide: Strong bases such as "n"-BuLi and NaNH can be used. Tetrolic acid is highly soluble in polar solvents