Oximes methanesulfonates

A. Cyatohexanone oxime methanesulfonate. A dry, 1-L, two-necked, round-bottomed flask is equipped with a gas inlet, rubber septum, and magnetic stirring bar. The flask is charged with 17.0 g (0.15 mol) of cyclohexanone oxime (Note 1) and flushed with argon, after which 300 mL of dichloromethane followed by 25 mL (0.18 mol) of triethylamine (Note 2) are injected through the septum into the flask. The solution is stirred and cooled to a temperature of -15 to -20°C in a dry ice-carbon tetrachloride bath, while 12.8 mL... 

The reaction in Part A proceeds in almost quantitative yield. Accordingly the crude cyclohexanone oxime methanesulfonate can be used without any purification. Prolonged standing at room temperature may cause serious decomposition. The crude material may be stored in a freezer, or as a dichloromethane solution In a refrigerator, and can be recrystallized from ether-hexane to give the white solid (mp 43-45°C)... 

Cyclohexanone oxime methanesulfonate Cyclohexanone, 0-(methylsulfonyl)oxime (10) (80053-69-6)... 

Oxime methanesulfonates are also suitable rearrangement substrates. Thus, the azetidinone oxime methanesulfonate (18) underwent smooth rearrangement upon exposure to basic alumina (equation... 

Treatment of O-benzylated ribono(arabino)-1,4-lactone oxime methanesulfonate 24 with NH3 in MeOH gave the crystalline 1,4-dihydro-1,2,4,5-tetrazines 25, (15)-eiythritol-l-yl isomer fiom the ribono and (l/ )-isomer from the arabino derivative <03HCA1488>. 

Enander, Sundwall, and Sorbo - -- 7 found that either oral or Intramuscular administration of 11 to rats at 500 or 100 mg/kg, respectively, increased by many times the urinary excretion of thiocyanate. From the amount of thlocynanate excreted above the base line, the quantity of hydrogen cyanide produced in metabolism of the oxime was calculated to be 0.1 mg/kg—a little more than one-third the LD50 for rats by lntraperitoneal injection. Urine from rats given 120 ymol of II intramuscularly or 400 pmol by mouth contained 3.9-7.8% N-methylpyridinlum-2-nltrlle methanesulfonate. When this compound was injected Intramuscularly into rats at 90 mg/kg, thiocyanate was excreted in the urine in Increased amounts. Also present in the urine was a metabolic product that yielded cyanide on acidification of the urine, similar to a cyanide-yielding metabolite of II found earlier. 

Crook, J.W., Cresthull, P., O Neil, H.W., Oberst, F.W. 1962. Chronic Intravenous toxicity of oximes 2-PAM chloride and 2-PAM methanesulfonate to dogs and rabbits. CRDLR 3153. 

Sldell, F.R., Groff, W.A., Ellin, R.I. 1969. Blood levels of oxime, excretion rates, and side effects produced by single oral doses of N-methylpyridlnium-2-aldoxime methanesulfonate (P2S) In humans. EATR 4256. 

Pralidoxime methanesulfonate (P2S), [C7H9N20]CH3C>3S, consists of hygroscopic crystals with a molecular weight of 232.28 and a melting point of lSSOC.H 1 7 This is reportedly the preferred oxime in the United Kingdom.73... 

Cholinesterase inhibition, the mechanism whereby a number of insecticides and nerve gases function, may be reversed by acid salts of pyridine-2-carbaldehyde oxime (51). The chloride (61JPS109, 64USP3155674), iodide (57USP2816113) and methanesulfonate... 

In parallel fashion, compound 267, made from 2,3 5,6-di-<9-isopropyl-idene-D-mannono-1,4-lactone by Reformatsky addition using ethyl bromo-acetate and zinc-silver graphite, undergoes ready elimination when converted to the methanesulfonic ester to give a separable mixture of the E- and Z-alkenes (268).251 Quite a different approach involves treatment of the 1-C-nitromannofuranosyl chloride, derived from the oxime of 2,3 5,6-di-O-isopropylidene-D-mannose, with the anion of diethyl malonate to give the disubstituted alkene 269.252... 

The indanone oximes (7) gave the aryl- and alkyl-migrated products (8) and (9) (equation 6), with the proportion of (9) itKteasing with increasing steric demand of arenc substituents at the 4- and 7-positions. Exposure of the ( )-oxime (10) to phosphorus pentoxide and methanesulfonic acid gave the product (11) of migration of the yn-alkyl group, presumably via the (Z)-isomer (equation 7). 

Several reagents for effecting the Beckmann rearrangement of the oxime (1) to give the lactam (2) have been evaluated with a view to the synthesis of a structural analog of the natural product, muscarine. The best results are obtained with a 10 1 mixture of methanesulfonic acid and phophorus pentoxide (equation 1). ... 

It has been almost 40 years since B. Wilson et al. observed that nucleophiles, oximes like hydroxamic acid, reactivated OP-inhibited AChE above and beyond that occurring from spontaneous reactivation, opening the way to a treatment for OP poisoning. The oxime registered for use in the United States is 2-PAM Cl (Protopam) its methanesulfonate salt (P2S) is used in Europe. Oxime therapy should be recommended with caution for carbamate poisonings. Although beneficial in the case of aldicarb, there is evidence that 2-PAM treatment increases the toxicity of carbaryl. 

Conversion of oximes to nitriles. Aldoximes are converted into nitriles in high yield by treatment with an ortho ester in the presence of a catalytic amount of an acid (methanesulfonic acid). The primary product is the oxime dialkyl ortho ester, which can be isolated in the absence of the acid catalyst. ... 

A. Pralidoxime chloride (2-PAM) is the only oxime currently approved for use in the United States. Oximes differ in their effectiveness against specific agents, dose, and side-effect profile. In the United Kingdom, the methanesulfonate salt of pralidoxime, P2S, is used. In other European countries and South Africa, TMB4 and obidoxime (Toxogonin) are employed. 2-PAM methiodide is used in Japan. 

A mixture of -heptaldehyde oxime and triethyl orthoformate containing a little methanesulfonic acid heated with distillation of the resulting ethanol and ethyl formate, then the residue distilled in vacuo -heptanoic acid nitrile. Y 95%. 

FIGURE 71.2 Chemical structure of pyridinium oximes used in treatment of OP compound poisoning. X indicates an anion (in PAM-2 it can be Cl", I", or methanesulfonate). 

In a 100-mI flask attached to a short distillation column are placed 15.0 ml (0.1 mole) of n-heptaldehyde oxime and 20.0 ml (0.12 mole) of triethyl orthoformate containing one drop of methanesulfonic acid. The mixture is heated gently to distil out ethyl formate and ethanol as they form. After the coproducts have been removed, the residue is distilled under reduced pressure at 70°-72 C (10 mm). Yield 95%. 

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