Method for the selective manufacture of N,N'-dimethyl piperazine
AssigneeTexaco Inc.
InventorsSteven H. Vanderpool, Peter S. Morford
Life of this patent
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Abstract
Piperazine, in solution in methanol may be substantially selectively converted to N,N'-dimethyl piperazine when using a catalyst composed of titania to which from about 0.5 to about 7 wt. % of phosphorous has been thermally chemically bonded in the form of phosphate linkages.
Claims8
A method for the manufacture of N,N'-dimethyl piperazine which comprises bringing a methanol solution of piperazine comprising about 2 to about 20 mols of methanol per mol of piperazine into contact with a catalyst at a temperature of about 250.degree.-400.degree. C. and a pressure of about 100 to about 3000 psig. for a period of time sufficient to substantially selectively convert at least about 75% of said piperazine to N,N'-dimethyl piperazine,
- said catalyst comprising titania having from about 0.5 to about 7 wt. % of phosphorus thermally chemically bonded to the surface thereof in the form of phosphate bonds.
A method for the manufacture of N,N'-dimethyl piperazine which comprises bringing a 10 to 50 wt. % solution of piperazine in methanol consisting essentially of about 2 to about 20 mols of methanol per mol of piperazine into contact with a catalyst at a temperature of about 250.degree.-400.degree. C. and a pressure of about 100 to about 3000 psig. for a period of time sufficient to substantially selectively convert about 76 to about 90% of said piperazine to N,N'-dimethyl piperazine,
- said catalyst consisting essentially of titania having from about 0.5 to about 7 wt. % of phosphorus thermally chemically bonded to the surface thereof in the form of phosphate bonds.
Dependencies are inferred from the claim text.