Methyl Methacrylate from Acetone Cyanohydrin

Methyl methacrylate is the liquid monomer that sets into acrylic glass (Perspex, Plexiglas). This is Example 1 of Crawford's ICI patent (US 2,042,458, 1936): acetone cyanohydrin is heated in strong sulphuric acid, then boiled with water and methanol to the ester, washed with brine, dried and distilled. Sulphur and tannic acid keep it from polymerising on the way. All parts are by weight. The picture: drawn by Youblob.