N-methyl morpholine oxide

Metal complexes combined with a suitable oxygen atom donor can often act as versatile and selective oxidation catalysts. The oxygen atom donors commonly used are N-methyl morpholine oxide 8.27 (see reaction 8.30), organic hydroperoxides, sodium hypochlorite, hydrogen peroxide, etc. Three such reactions of industrial relevance are shown by 8.30, 8.31, and 8.32. Obviously these reactions are catalytic with respect to the metal complex but stoichiometric with respect to the oxygen atom donor. 

Scheme 2 Mechanism of the ruthenium-catalyzed oxidation of fatty alcohols to aldehydes (MM = N-methylmorpholine MMO = N-methyl-morpholine oxide).

CHs)s N- 0, N-Methyl-morpholine oxide N-Nitramines Cu, Ag, Ag-Cu, Cu,Mg Copper oxide, Cu OyCuO A92O Cu(0H)2 AgOH... 

Other additives, such as dialkyl sulfides, also improve the yields of intermolecular Pauson-Khand reactions. One reaction that formed the Pauson-Khand product in 85% yield in the presence of methylbutyl sulfide, but which did not form the Pauson-Khand product in the presence of added N-methyl morpholine oxide, is shown in Scheme 17.35. 

Synonyms 4-Methylmorpholine-4-oxide 4-Methylmorpholine-N-oxide N-Methyl-morpholine oxide 4-Methylmorpholine 4-oxide monohydrate 4-Methylmorpholine N-oxide monohydrate Morpholine, 4-methyl-, 4-oxide NMMO NMO monohydrate... 

There are modem processes in development and have already passed the pilot stage to produce fibers by dissolving cellulose in a mixture of N-methyl morpholine oxide (NMMO) and water. The solution is filtered, spun and precipitated in an aqueous bath. NMMO can be recycled with a yield of 99%. The resulting fiber has the highest dry and wet strength of all c. Fibrillation is still a problem. There could be large outlets for such a fiber. 

There are already encouraging alternatives. Processes with N-methyl morpholine oxide/water as a solvent for cellulose (- cellulose fibers) are now in commercial use. These fibers have been given the generic name Lyocell . Under these circumstances, the importance of regenerated or modified cellulose fibers may increase once again. 

Newcell A process for making reconstituted cellulose fibers by dissolving cellulose in N-methyl morpholine N-oxide and injecting the solution into water. Invented in 1977 by Akzona, NC. 

Acyl nitroso compounds react with 1, 3-dienes as N-O heterodienophiles to produce cycloadducts, which have found use in the total synthesis of a number of nitrogen-containing natural products [21]. The cycloadducts of acyl nitroso compounds and 9,10-dimethylanthracene (4, Scheme 7.3) undergo thermal decomposition through retro-Diels-Alder reactions to produce acyl nitroso compounds under non-oxidative conditions and at relatively mild temperatures (40-100°C) [11-14]. Decomposition of these compounds provides a particularly clean method for the formation of acyl nitroso compounds. Photolysis or thermolysis of 3, 5-diphenyl-l, 2, 4-oxadiazole-4-oxide (5) generates the aromatic acyl nitroso compound (6) and ben-zonitrile (Scheme 7.3) [22, 23]. Other reactions that generate acyl nitroso compounds include the treatment of 5 with a nitrile oxide [24], the addition of N-methyl morpholine N-oxide to nitrile oxides and the decomposition of N, O-diacylated or alkylated N-hydroxyarylsulfonamides [25-29]. 

The oxidation of alcohols to carbonyl compounds has been studied by several authors and a variety of methods have been used. Papers concerned vith such oxidations are illustrated (Scheme 3.26). Good results have been obtained using pyridinium chlor-ochromate (PCC) adsorbed onto silica gel for the selective oxidation of unsaturated substrates e.g. terpene [135] and furanyl derivatives [136]. Steroidal homoallylic alcohols can be converted to the corresponding 4-ene-3,6-diones using tetrapropylammo-nium per-ruthenate (TPAP) in catalytic amounts [137]. In this case, the oxidising agent is N-methyl morpholine N-oxide (NMO). 

Chanzy and Peguy (13) were the first to report that cellulose forms a lyotropic mesophase. They used a mixture of N-methyl-morpholine-N-oxide (MMNO) and water as the solvent. Solution birefringence occurred at concentrations greater than 20% (w/w) cellulose. The concentration at which an ordered phase formed increased as the cellulose D.P. decreased. The persistence length of cellulose in MMNO-H2O is not known but presumably it has an extended chain configuration in this solvent. Again the question arises as to what is the relevant axial ratio to be used for cellulose. This will be discussed further below. 

The very sensitive ether peroxide test strips (Merckoquant, Art. No. 10011), available from E. Merck, Darmstadt, are used. If the test is still positive at this point, an additional 0.2 ml. of N-methyl morpholine is added. Stirring and heating at 75° are continued for another 5 hours. Remaining peroxide renders the work-up and drying of the product potentially hazardous. N-Methylmorpholine N-oxide (1) and hydrogen peroxide form a strong 1 1 complex. In the reaction with osmium tetroxide, this complex produces conditions similar to those of the Milas reaction,7 and some ketol formation may result. 

Osmium tetroxide-N-Methyl-morpholine N-oxide, 222 Osmium tetroxide-Trimethylamine N-oxide-Pyridine, 223 Palladium Compounds Benzylchlorobis(triphenylphosphine)-palladium(II), 30 Bis (ace tonitrile) chloronitropalla-dium(II)-Copper(II) chloride, 33 Bis(acetonitrile)dichloropalladium(II), 33, 211, 236... 

The Upjohn Dihydroxylation allows the sy/i-selective preparation of 1,2-diols from alkenes by the use of 0s04 as a catalyst and a stoichiometric amount of an oxidant such as NMO (N-methyl morpholine- JV-Oxide). 

Oxidation of alcohols. Griffith and Ley1 report various improvements for use of this reagent for catalytic oxidation of alcohols in combination with N-methyl-morpholine N-oxide as reoxidant. In general, the yields with this oxidant are higher than those obtained by the Swern reagent. 

TPAP = Tetrapropylammonium perruthenate DMAP = 4-dimethylaminopyridine. NHO = N-methyl morpholine N-oxide ... 

Marsano, E., Corsini, P., Arosio, C., Boschi, A., Mormino, M., and Freddi, G. "Wet spinning of Bombyx mori silk fibroin dissolved in N-methyl morpholine N-oxide and properties of regenerated fibres". Int. J. Biol. Macromol. 37(4), 179-188 (2005). 

Alceru [Alternative cellulose Rudolstadt] A process for making cellulosic filaments and staple fibers. The cellulose is first dissolved in an aqueous solution of N-methyl morpholine N-oxide (NMMNO) and then spun. Developed by the Thiiringische Institut fur Textil- and Kunstoff-Forschung e.V. Rudolstadt, Germany, and Zimmer (Frankfurt) from 1987. A pilot plant was built in April, 1998 and a commercial plant was planned for installation in Baoding, China in 2005. A superabsorbent version of the fiber has been developed by Stockhausen. The fiber is now made commercially by Sea Cell GmbH, a subsidiary of Zimmer. See also Lyocell. 

To a solution of 7 (458 mg, 1.7 mmol) and N-methyl morpholine A-oxide (244 mg) in t-butanol (1 mL), a few crystals of osmium tetraoxide dissolved in THF (1.5 mL) were added. After 3 days 40% aqueous solution of NaHSOj (3 mL) was added, the mixture was stirred for additional 30 min, and extracted with ethyl acetate (3 x 20 mL). The extracts were dried (MgS04) and concentrated to dryness. The residue was purified by chromatography on a silica gel column with light petroleum-ether-methanol (4 5 0.5) to yield 9 (371 mg, 72%) mp 89.5° (from a mixture of hexane and ethyl acetate), [a] + 52° (c 1.0, CHCI3). 

The chiral directing groups are pinanediols derived from osmium tetroxide-cat-alyzed oxidation of either (+)-a-pinene or (-)-a-pinene with trimethylamine oxide or with NMO (N-methyl-morpholine-N-oxide). The (s) and (r) notations shown in the abbreviations refer to the configuration of the chiral center in the a-chloroboronic ester using the appropriate pinanediol. 

The use of a cooxidant can reduce the amount of osmium required for a complete reaction of an alkene from stoichiometric to catalytic some examples of oxidants that can achieve this are peroxides [20, 22, 35, 37, 42-44] including hydrogen peroxide [20, 42], chlorates [45], periodate [46, 47], hypochlorite [48], N-methyl-morpholine-N-oxide (NMMO) [22, 34, 35, 37, 49], potassium ferricyanide [50, 51], and even air [52, 53]. 

Shaded cells indicate compatibility of polymer with solvent or crosslinker PLA poly(lactic acid), PGA poly(glycolic acid) PLGA poly(lactic-co-glycolic acid), PCL poly(e-caprolactone), PEU poly(ester urethane), PEEUU poly(ester ether urethane), PVA poly(vinyl alcohol), PEO poly(ethylene oxide), HA hyaluronic acid, DMF W,W-dimethylformamide, A4 acetic acid, FA formic acid, DCM dichloromethane, HFIP hexafluoroisopropanol, THF tetrahydrofuran, GA glutaraldehyde, NMMO N-methyl-morpholine A -o, idc/water (NMMO/water)... 

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