Claims
- 1. The method of preparing an arylketoamine, which comprises:
- (a) providing an arylalkanone compound of the formula: ##STR5## in which R represents hydrogen or a C.sub.1 -C.sub.8 alkyl or cycloalkyl and Ar represents an aromatic phenyl radical unsubstituted, or substituted at the ortho and/or para position, or naphthyl radical unsubstituted or substituted at one or more of the 1, 3, 6, and 7 positions, wherein the substituents, one or more, are selected from the group of hydroxyl, alkoxy, alkyl, phenyl, benzyl, and aryloxy radicals, wherein the alkyl in the alkyl-containing substituent(s) is a branched or unbranched C.sub.1 -C.sub.8 alkyl radical and any such alkyl radical as well as the phenyl and benzyl radicals may be optionally substituted with one or more substituents selected from hydroxyl, sulfonic acid, and sulfinic acid radicals, the phenyl and benzyl substituents also or alternatively being optionally substituted with one or more C.sub.1 -C.sub.8 alkyl or C.sub.1 -C.sub.8 alkoxy, or both, radicals,
- (b) reacting said arylalkanone with a lower alkyl nitrite in the presence of a strong acid and a dipolar aprotic solvent to produce a reaction mixture which includes an arylisonitrosoalkanone reaction product and water of reaction in said solvent,
- (c) removing water from said reaction mixture, and
- (d) contacting said dried reaction product with hydrogen and a liquid carboxylic acid, which is capable of substantially dissolving said reaction mixture, in the presence of a hydrogenation catalyst comprising a transition metal catalyst on an inert support.
- 2. The method of claim 1, wherein the amount of said transition metal present ranges from about 0.05% by weight to about 1.5% by weight of said compound of step a).
- 3. The method of claim 2, wherein said transition metal is selected from the group consisting of platinum, palladium, nickel, rhodium, and combinations thereof.
- 4. The method of claim 1, wherein said step (c) comprises evaporating said water of reaction.
- 5. The method of claim 1, wherein said step (c) comprises contacting said reaction mixture with a drying agent for absorbing said water of reaction.
- 6. The method of claim 1, wherein said step (c) comprises contacting said reaction mixture with a solid adsorbent for adsorbing said water of reaction.
- 7. The reaction of claim 1 in which said aryltalkanone is o- or .rho.-hydroxyacetophenone, said strong acid in step (b) is hydrochloric acid, and said hydrogenation catalyst is palladium on a carbon support.
- 8. The method of claim 7 in which said solvent of step (b) is selected from dimethylsulfoxide, acetonitrile, dimethylformamide, diethylacetamide and hexamethylphosphoric acid triamide.
- 9. The method of claim 8 in which said palladium, exclusive of said carbon support, is present in a quantity ranging from about 0.005% by weight to about 1.5% by weight based on the weight of said o- or .rho.-hydroxyacetophenone, and wherein said step (d) reaction is conducted under hydrogen pressure ranging from about 1.0 psi to about 300 psi at temperatures in the range of from about 10.degree. C. to about 35.degree. C., and the liquid carboxylic acid is acetic acid.
Parent Case Info
This is a divisional of copending application Ser. No. 08/191,849, now U.S. Pat. No. 5,349,090.
US Referenced Citations (8)
Divisions (1)
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Number |
Date |
Country |
Parent |
191849 |
Feb 1994 |
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