Methacrylonitrile, from ammoxidation

Improvements in acrylonitrile yield are also reported with other vapor phase promoters. A patent assigned to Monsanto Co. (125) describes the use of sulfur and sulfur-containing compounds in the feed gas mixture for production of acrylonitrile or methacrylonitrile from propane or isobutane over metal oxide catalysts. Examples of effective sulfur-containing compounds include alkyl or dialkyl sulfides, mercaptans, hydrogen sulfide, ammonium sulfide, and sulfiir dioxide. Best results are apparently achieved using a molar ratio of sulfur (or sulfur compound) to hydrocarbon of 0.0005 1 to 0.01 1. Nitric oxide has also been examined as a gas-phase promoter for propane and isobutane ammoxidation (126). However, it does not appear to be as effective as halogen or sulfur. Selectivities to acrylonitrile from propane are only about 30% over an alumina-supported chromium-nickel oxide catalyst. 

Hinago Hidenori, K. and Satoru Komada, Y. (2(X)0). US Patent 6143916, Ammoxidation catalyst for nse in producing acrylonitrile or methacrylonitrile from propane or isobutane by ammoxidation (Asahi Kasei Kogyo Kabushiki Kaisha, Japan). 

Ammoxidation, a vapor-phase reaction of hydrocarbon with ammonia and oxygen (air) (eq. 2). can be used to produce hydrogen cyanide (HCN), acrylonitrile, acetonitrile (as a by-product of acrylonitrile manufacture), methacrylonitrile, benzonitrile, and toluinitriles from methane, propylene, butylene, toluene, and xylenes, respectively. See also Acrylonitrile and Methacrylic Acid and Derivatives,... 

Whereas the ammoxidation of lower hydrocarbons leads to more large-scale products such as acrylonitrile [7] or methacrylonitrile [8], the ammoxidation of substituted aromatics or heteroaromatics opens the way for the synthesis of fine chemicals or intermediates for fine-chemical syntheses. A variety of pharmaceuticals, pesticides, dyestuffs, and other speciality products are produced from substituted aromatic or heteroaromatic nitriles [e.g. 9,10]. 

Methacrylonitrile, CH2=C(CH3)CN, can also be prepared by several routes. Some commercial processes are based on acetone cyanohydrin intermediate and others on dehydrogenation (or oxydehydrogenation) of isobutyronitrile. It is also prepared from isobutylene by ammoxidation ... 

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