[2278-22-0] · C2H3NO5 · Peroxyacetyl Nitrate · (MW 121.06)
Alternate Name: acetyl nitro peroxide; PAN.
Physical Data: mp -48.5 °C; bp 104 °C (extrapolated).
Solubility: sol pentane, benzene, CCl4, CHCl3, acetone.
Form Supplied in: not available commercially.
Analysis of Reagent Purity: GLC.6
Preparative Methods: to a stirred mixture of Peracetic Acid (5 mmol) and 10-15 mL of dry pentane maintained at -5 to 0 °C is added 90% Nitric Acid (1 equiv) and Sulfur Trioxide (30% SO3 in H2SO4, 1 equiv). The reaction mixture is stirred at -5 °C for 3 h and then treated with ice water. The organic layer is dried over MgSO4 at -20 °C. The yield of unpurified PAN in pentane solution is 39%.1
Handling, Storage, and Precautions: explosions occur when pure PAN is condensed as a liquid.7 PAN is thermally unstable above 0 °C.8 Purified PAN is stored as an N2-diluted gas at 1000 ppm, 100 psi in gas cylinders at 0 °C.4,9 Use in a well ventilated fume hood.10
PAN is formed in polluted air by the photochemical action of sunlight on hydrocarbons and nitrogen oxides. It is an eye irritant and it also damages plants. It reacts with biologically important materials such as enzymes. Hence, there is considerable interest in studying its reactions.7
PAN is a convenient source of radicals; it decomposes rapidly (t
Reaction of PAN with alkenes yields epoxides (eq 2).2 PAN reacts with either cis- or trans-stilbene to give only (>95%) trans-stilbene oxide (eq 3).
The acid-sensitive acenaphthylene oxide (2) has been prepared in 50% yield by epoxidizing acenaphthylene. PAN may find applications in the synthesis of acid sensitive oxides.
Aldehydes are oxidized by PAN in CDCl3, CCl4, benzene, or acetone to the corresponding acids in good yield.3 The reaction proceeds by a radical mechanism. Ketones are not oxidized by PAN.
When liquid n-propylamine is injected into a solution of PAN (0.5 M in CDCl3), vigorous evolution of oxygen is observed.5 The reaction is complete in less than 1 min after mixing the reactants; the amide (3) is formed (yield >90%).
When 0.4 M KOH in benzene-methanol (9:1) is added to dilute solutions of PAN (0.2-0.3 M in benzene), there is vigorous evolution of oxygen (eq 4).11 Singlet oxygen, which may be important in oxidations involving PAN, has been shown to be a product of this reaction.
Thiols are oxidized by PAN to disulfides; cysteine (4) is oxidized to cystine.4 Sulfides are oxidized to sulfoxides (e.g. methionine (5) to methionine sulfoxide). PAN rapidly oxidizes dimethyl sulfide to DMSO (t
Considering the hazards involved in handling large quantities of PAN, it is not yet particularly useful in synthetic organic chemistry. Oxidation reactions presented above can be carried out conveniently and in good yields using m-Chloroperbenzoic Acid or Hydrogen Peroxide.
A. Somasekar Rao & H. Rama Mohan
Indian Institute of Chemical Technology, Hyderabad, India