Search results
Results from the WOW.Com Content Network
Acetone cyanohydrin (ACH) is an organic compound used in the production of methyl methacrylate, the monomer of the transparent plastic polymethyl methacrylate (PMMA), also known as acrylic. It liberates hydrogen cyanide easily, so it is used as a source of such.
The structure of a general cyanohydrin. In organic chemistry, a cyanohydrin or hydroxynitrile is a functional group found in organic compounds in which a cyano and a hydroxy group are attached to the same carbon atom. The general formula is R 2 C(OH)CN, where R is H, alkyl, or aryl.
In organic chemistry, a cyanohydrin reaction is an organic reaction in which an aldehyde (−CH=O) or ketone (>C=O) reacts with a cyanide anion (N≡C −) or a nitrile (−C≡N) to form a cyanohydrin (>C(OH)C≡N). For example:
Acetone (2-propanone or dimethyl ketone) is an organic compound with the formula (CH 3) 2 CO. [22] It is the simplest and smallest ketone (R−C(=O)−R').It is a colorless, highly volatile, and flammable liquid with a characteristic pungent odour, very reminiscent of the smell of pear drops.
The principal route begins with the condensation of acetone and hydrogen cyanide: [4] (CH 3) 2 CO + HCN → (CH 3) 2 C(OH)CN. Sulfuric acid then hydrolyzes acetone cyanohydrin (ACH) to a sulfate ester-adduct, which is cracked to the ester: (CH 3) 2 C(OH)CN + 2H 2 SO 4 → ((CH 3) 2 C(OSO 3 H)C(O)NH 2 ·H 2 SO 4 → (CH 3) 2 C(OSO 3 H)C(O)NH 2 ...
In the most common route, methacrylic acid is prepared from acetone cyanohydrin, which is converted to methacrylamide sulfate using sulfuric acid.This derivative in turn is hydrolyzed to methacrylic acid, or esterified to methyl methacrylate in one step.
In transhydrocyanation, an equivalent of HCN is transferred from a cyanohydrin, e.g. acetone cyanohydrin, to another activated HCN acceptor. The transfer is an equilibrium process, initiated by base. The reaction can be driven by trapping or a superior acceptor, such as an aldehyde. [9]
The method is very similar to the modern route using alkyl and arylcyanates. The 5,5-dimethyl compound can also be obtained from acetone cyanohydrin (also discovered by Urech: see cyanohydrin reaction) and ammonium carbonate. [3] This reaction type is called the Bucherer–Bergs reaction. [4] [5]