Acyl nitrates decomposition

Attempts to follow a published method for nitrating phthalic anhydride in sulfuric acid at 80-100°C with fuming nitric acid caused an eruptive decomposition to occur after 2 h delay [1], The hazard can be eliminated by use of a smaller excess of nitrating acid at 55-65°C [2], Acyl nitrates were suggested as a possible cause of the delayed eruption [3],... 

Although acetyl and other acyl nitrates are dangerously explosive, in solution they undergo smooth thermolysis to alkyl nitrates with one less carbon atom (Scheme 154) a number of methods are discussed for the preparation of acyl nitrates. Thermolysis is conducted at high temperature to minimize the alternative mode of decomposition, production of carboxylic acid anhydrides and dinitrogen pentoxide. 

Poly(azophenylene-o-carborane) (see 6) has been prepared from diphenyl-o-carborane by means of nitration, reduction, and acylation to initially give 1,2-bis(/ -nitroso-acetylaminophenyl)-o-carborane (NAFC). Rapid decomposition in solution affords phenylene amino phenyl carborane (PAFC) by recombination of phenylene and azophenylene radicals.40 These radicals have also been utilized to form copolymers of carborane-containing copolymers from monomers polymerizable via radical mechanisms. Thus, copolymers of polystyrene and poly(azophenylene) can be readily formed by means of emulsion copolymerization of styrene with NAFC decomposition products. 

Calculations by the Pariser-Parr-Pople method on the quinoneimine obtained by Fremy s salt oxidation of dibenz[6,/]azepine indicate that the carbon adjacent to the carbonyl group is the most nucleophilic center. This is confirmed by nitration [Cu(N03)2-Ac0H] and bromination [NBS-(PhC0)202] studies, in which the 1-substituted derivatives are obtained. However, acylation by Vilsmeier or Friedel-Crafts reaction fails, extensive decomposition of the ring system taking place. 

Since the data for para nitration (Knowles et al., 1960) and acetylation are on a firm experimental basis these small deviations and trends are almost certainly real. Two interpretations are possible. The isotope effect observed for acetylation (Jensen, 1955) suggests that the trend may have its origin, in this case, in the competitive rates of formation and decomposition of the benzenium ions. The observation of a Baker-Nathan order, p-Me> p-t-Bu, is presumably a reflection of the greater stabihty of the l-acyl-4-methylbenzenium ion (27) compared to the... 

DIEXHYLENE GLYCOL METHYL ETHER ACETATE (629-38-9) Combustible liquid (flash point 180°F/98°C). Moisture may cause decomposition with formation of acetic acid. Reacts violently with strong oxidizers, permanganates, peroxides, ammonium persulfate, bromine dioxide, calcium chlorate, chlorosulfonic acid, oleum, sulfuric acid, nitric acid, perchloric acid, and other strong acids. Incompatible with acyl halides, aliphatic amines, alkalis, boranes, isocyanates, nitrates. May form shock-sensitive mixtures with silver, cobalt, chlorinated hydrocarbons, nitromethane, chromium compounds. Attacks some plastics, rubber, and coatings. Attacks copper, brass, zinc. 

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