Albemarle Corporation

Ethyl Corporation

Amoco Corporation

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Bp Amoco Corporation

Kevin J Theriot

Robert G Irwin

Mahmood Sabahi

Ronald L Shubkin

Brian F Becnel

Edward A Burt

Lawrence H Shepherd, Jr

Niomi L Krzystowczyk

Yueh-Dong Chen

Nitrones are produced by reaction of primary amine with aldehyde or ketone, in the presence of a transition metal-containing oxidation catalyst, and a peroxidic compound. The nitrone can then be reacted with a vinylaromatic compound to produce a 2-hydrocarbyl-5-arylisoxazolidine. Both such reactions can be conducted concurrently by including the vinylaromatic compound in the initial reaction mixture. Hydrogenation of the 2-hydrocarbyl-5-arylisoxazolidine, e.g., using hydrogen and a palladium-carbon catalyst, forms an N-hydrocarbyl-3-aryl-3-hydroxypropylamine. Such reactions enable, inter alia, synthesis of the racemic hydrochloride salt of N-methyl-3-phenyl-3-[4-trifluoromethyl)phenoxy]-propylamine, known generically as fluoxetine hydrochloride, a widely used antidepressant.

Preparation and uses of hydrocarbylnitrones

Alpha-olefin oligomers are produced by oligomering alpha-olefin monomer with a catalyst system comprising boron trifluoride, a protic promoter, and a special type of modifier. The modifier is a compound that satisfies the following criteria: (a) it has at least one moiety in which a carbonyl group is directly bonded to a nitrogen atom which is in turn bonded to two separate carbon atoms, (b) it is devoid of any nitrogen atom other than a nitrogen atom that is either (i) directly bonded to two separate carbon atoms and to a carbonyl group or (ii) is triply bonded to a single carbon atom, and (c) it is devoid of any protonic functional substituent. These modifiers control the oligomer product distribution and provide higher percentages of lower oligomers, especially dimers.

Olefin oligomerization process

(a) An alkali metal base (hydroxide, oxide, carbonate, bicarbonate or sesquicarbonate), an acid addition salt of N-methylhydroxylamine, and (iii) water are mixed together to form a reaction mixture in which the acid of the acid addition salt has been neutralized. (b) Reaction mixture from (a) and formaldehyde or formalin are mixed together and the resultant mixture is subjected to reaction conditions that produce a reaction mixture in which N-methylnitrone has been formed. (c) Reaction mixture from (b) and styrene are mixed and the resultant mixture to subjected to reaction conditions that produce a reaction mixture in which 2-methyl-5-phenylisoxazolidine has been formed. Preferably, 2-methyl-5-phenylisoxazolidine formed in (c) is hydrogenated such that N-methyl-3-phenyl-3-hydroxypropylamine is formed, which in turn is reacted with 4-halobenzotrifluoride such that N-methyl-3-phenyl-3-�4-trifluoromethyl)phenoxy!propylamine is formed. Conversion of the N-methyl-3-phenyl-3-�4-trifluoromethyl)phenoxy!propylamine to its racemic hydrochloride salt provides fluoxetine hydrochloride, a widely used antidepressant.

Preparation and use of 2-methyl-5-phenylisoxazolidine

Activated aromatic compounds are more economically ring brominated by reacting the compounds with a sulfoxide/HBr brominating agent while removing water from the reaction mixture. The water removal provides high conversions and yields when employing stoichiometric quantities of reactants.

Aromatic bromination process

In producing nabumetone or precursor thereof, use is made of 2-bromo-6-methoxynaphthalene formed by (a) methylating 6-bromo-2-naphthol with methyl bromide or methyl chloride, in a halogen-free liquid solvent comprising at least about 40% by weight of one or more compounds of the formula RZ where R is a hydrogen atom or an alkyl group, and Z is a hydroxyl group or a cyanide group with the proviso that if Z is a cyanide group, R is an alkyl group, and in the presence of at least one strong base; and (b) recovering and purifying 2-bromo-6-methoxynaphthalene so formed. The 6-bromo-2-naphthol in turn is preferably formed by reacting 1,6-dibromo-2-naphthol with hydrogen in a halogen-containing liquid solvent comprising at least about 50% by weight of (A) at least one liquid organic halide solvent in which the halogen content has an atomic number of 35 or less or (B) a mixture of water and at least one such liquid organic halide solvent, and in the presence of catalytic amounts of (i) a tungsten carbide-based catalyst, and (ii) at least one phase transfer catalyst, most preferably while purging HBr from the reaction mixture as it is formed. In this way, the quantities of by-products formed in the overall operation are reduced, the need for use of excess iron and/or dimethyl sulfate as reaction components is avoided, and the overall efficiency of plant operation is improved especially when conducted on a large scale.

Production of nabumetone or precursors thereof

Oxidation of secondary amines with hydrogen peroxide and sodium tungstate is reported to give good yields of nitrones. However, when using dimethylamine in this manner, a considerable amount of N,N-dimethylformamide was produced as a co-product. To more selectively produce N-methylnitrone from dimethylamine, a two-step process is used which comprises (a) mixing together dimethylamine and a peroxidic compound, and subjecting the resultant mixture to reaction conditions effective to form a reaction mixture in which N,N-dimethylhydroxylamine has been formed; and (b) mixing together (i) reaction mixture from (a), (ii) a peroxidic compound, and (iii) a transition metal-containing oxidation catalyst, and subjecting the resultant mixture to reaction conditions effective to form a reaction mixture in which N-methylnitrone has been formed. Highest yields of N-methylnitrone are achieved by conducting step (b) at a pH in the range of 7 to about 12, and at a temperature in the range of about -10.degree. to about 100.degree. C.

Preparation and uses of N-methylnitrone

A mixture formed from an alkoxy-2-naphthaldehyde (e.g., 6-methoxy-2-naphthaldehyde), acetone, and aqueous NaOH and/or KOH is heated at about 20.degree. to about 56.degree. C. for about 0.25 to about 2 hours such that the conversion of monoalkoxy-substituted 2-naphthaldehyde is at least 97% and the yield of (alkoxy-substituted 2-naphthyl)-3-buten-2-one is at least 95% based on the monoalkoxy-substituted 2-naphthaldehyde used in forming the mixture. The (alkoxy-substituted 2-naphthyl)-3-buten-2-one can be hydrogenated using, for example, a Pd/C catalyst to form the corresponding saturated ketone. The process enables efficient production of precursors of nabumetone and related pharmaceuticals by a clean, highly efficient reaction.

Production of alkoxynaphthyl-substituted ketones from naphthaldehydes

In producing (.+-.)-2-(6-methoxy-2-naphthyl)propionic acid or precursor thereof from 2-bromo-6-methoxynaphthalene, use is made of 2-bromo-6-methoxynaphthalene formed by (a) methylating 6-bromo-2-naphthol with methyl chloride in a solvent comprising one or more compounds, RZ, where R is a hydrogen atom or an alkyl group, and Z is --OH or --CN provided that if Z is --CN, R is alkyl, and in the presence of a strong base; and (b) recovering and purifying 2-bromo-6-methoxynaphthalene so formed. Preferably, the 6-bromo-2-naphthol is formed by (1) reacting 1,6-dibromo-2-naphthol with hydrogen, in a solvent comprising (a) organic halide in which the halogen has an atomic number of 35 or less or (b) a mixture of water and such organic halide, and in the presence of catalytically effective amounts of (i) a tungsten carbide-based catalyst, and (ii) phase transfer catalyst; and (2) separating 6-bromo-2-naphthol from the organic halide solvent so that the 6-bromo-2-naphthol is substantially free of halogen-containing impurities before use in the above methylation reaction. This technology makes possible reductions in quantities of co-products formed, eliminates need for use of excess iron and/or dimethyl sulfate as reaction components, and makes possible improvements in plant operating efficiency. Precursors of (.+-.)-2-(6-methoxy-2-naphthyl)propionic acid formed from such 2-bromo-6-methoxynaphthalene are Grignard reagent of 2-bromo-6-methoxynaphthalene, bis(6-methoxy-2-naphthyl)zinc, 6-methoxy-2-naphthylzinc halide, 6-methoxy-2-naphthyllithium, 6-methoxy-2-naphthylcopper(I), bis(6-methoxy-2-naphthyl)cadmium, 6-methoxy-2-naphthylcadmium halide, and 6-methoxy-2-vinylnaphthalene.

Production of racemic 2-(6-methoxy-2-naphthyl) propionic acid of

Alpha-olefin oligomers are produced by oligomerizing an alpha-olefin monomer with a catalyst system comprising boron trifluoride, a protic promoter, and a modifier which is (a) at least one 1,3-dioxolane, or (b) at least one 1,3-dioxane, or (c) a combination of (a) and (b). Use of these modifiers in the BF.sub.3 -catalyzed oligomerization makes it possible to modify the promoted catalytic reaction so that product containing as much as 50% or more of dimer can be produced at high conversions, at modest reaction temperatures, and in short reaction periods.

Alpha-olefin oligomer is prepared by contacting an alpha-olefin monomer which contains from about 6 to about 20 carbon atoms with a catalyst system comprising boron trifluoride, a protic promoter, and an organic sulfone, sulfoxide, carbonate, thiocarbonate, or sulfonate. Oligomer containing as much as 50% or more of dimer can be produced at high conversions, at modest reaction temperatures, and in acceptably short reaction periods.

Alpha-olefin oligomers are prepared by a process which comprises contacting an oligomerizable olefin monomer with a catalyst system comprising a catalytic amount of boron trifluoride, a protic promoter, and an organic modifier selected from the group consisting of phosphate, thiophosphate, phosphine oxide, and phosphine sulfide. The oligomerizable olefin monomer is a C.sub.6 to C.sub.20 linear olefin comprising at least 50 mole % alpha olefin.

A process for making an .alpha.-olefin oligomer comprises contacting a C.sub.6 to C.sub.20 .alpha.-olefin monomer with a catalyst which includes boron trifluoride, a protic promotor and a polyether.

Activated carboxylic acids and esters such as pentafluorobenzoic acid are rapidly decarboxylated in high yields by reacting the acid or ester with an alkanolamine reagent which catalyzes the reaction.

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Baton Rouge, LA, United States of America

Kevin J Theriot