US2002177739A1PendingUtilityA1

Method for the preparation of sevoflurane

Assignee: MEDEVA PHARMACEUTICALS PA INCPriority: Aug 18, 1997Filed: Jul 11, 2002Published: Nov 28, 2002
Est. expiryAug 18, 2017(expired)· nominal 20-yr term from priority
Inventors:Ross C. Terrell
C07C 41/22
45
PatentIndex Score
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Claims

Abstract

A method for the preparation of sevoflurane which comprises (a) providing a liquid mixture of (CF 3 ) 2 CHOCH 2 Cl, hydrogen fluoride, and an amine and (b) reacting the mixture, to form (CF 3 ) 2 CHOCH 2 F.

Claims

exact text as granted — not AI-modified
What is claimed is:  
     
         1 . A method for the preparation of sevoflurane which comprises: 
 (a) providing a liquid mixture of (CF 3 ) 2 CHOCH 2 Cl, hydrogen fluoride, and an amine; and    (b) reacting the mixture;    to form (CF 3 ) 2 CHOCH 2 F.    
     
     
         2 . The method of  claim 1 , wherein the mixture is reacted by heating.  
     
     
         3 . The method of  claim 1 , wherein the mixture is reacted by heating at 40° C. to 80° C.  
     
     
         4 . The method of  claim 1 , wherein the mixture is reacted by heating at 55° C. to 65° C.  
     
     
         5 . The method of  claim 1 , wherein the amine is selected from a primary amine, a secondary amine, or a tertiary amine.  
     
     
         6 . The method of  claim 5 , wherein the amine is selected from propylamine or diethylamine.  
     
     
         7 . The method of  claim 5 , wherein the amine is a tertiary amine.  
     
     
         8 . The method of  claim 7 , wherein the tertiary amine is a trialkylamine.  
     
     
         9 . The method of  claim 8 , wherein the trialkylamine is selected from triethylamine, tripropylamine, triisopropylamine, tributylamine, dimethyl ethyl amine, di-isopropyl ethyl amine, or mixtures thereof.  
     
     
         10 . The method of  claim 1 , wherein the amine is a cyclic amine.  
     
     
         11 . The method of  claim 10 , wherein the cyclic amine is selected from pyrrolidine, N-methyl pyrrolidine, or piperidine.  
     
     
         12 . The method of  claim 1 , wherein the mixture comprises (CF 3 ) 2 CHOCHCl 2 .  
     
     
         13 . The method of  claim 12 , wherein the mixture comprises from 0.01 to 20 percent by weight of (CF 3 ) 2 CHOCHCl 2 .  
     
     
         14 . The method of  claim 1 , wherein the mixture comprises water.  
     
     
         15 . The method of  claim 14 , wherein the mixture comprises 1 to 25 percent by weight of water.  
     
     
         16 . The method of  claim 14 , wherein the mixture comprises 1 to 15 percent by weight of water.  
     
     
         17 . The method of  claim 14 , wherein the mixture comprises 3 to 10 percent by weight of water.  
     
     
         18 . The method of  claim 1 , wherein the mole ratio of the (CF 3 ) 2 CHOCH 2 Cl to the hydrogen fluoride is from 1:1 to 1:2.  
     
     
         19 . The method of  claim 1 , wherein the mole ratio of the (CF 3 ) 2 CHOCH 2 Cl to the amine is from 1:0.3 to 1:2.  
     
     
         20 . The method of  claim 3 , wherein the mixture is reacted for 4 to 12 hours.  
     
     
         21 . The method of  claim 3 , wherein the mixture is reacted for 4 to 10 hours.  
     
     
         22 . The method of  claim 3 , wherein the mixture is reacted for 4 to 7 hours.  
     
     
         23 . The method of  claim 1 , wherein the yield of the reaction is at least 50 percent.  
     
     
         24 . The method of  claim 1 , wherein the yield of the reaction is at least 65 percent.  
     
     
         25 . The method of  claim 1 , wherein the yield of the reaction is at least 75 percent.  
     
     
         26 . The method of  claim 1 , wherein the conversion of the reaction is at least 50 percent.  
     
     
         27 . The method of  claim 1 , wherein the conversion of the reaction is at least 60 percent.  
     
     
         28 . The method of  claim 1 , wherein the conversion of the reaction is at least 70 percent.  
     
     
         29 . The method of  claim 1 , comprising separating the (CF 3 ) 2 CHOCH 2 F from the mixture after the mixture has reacted by washing the mixture with water.  
     
     
         30 . The method of  claim 1 , comprising separating the (CF 3 ) 2 CHOCH 2 F from the mixture by steam distillation.  
     
     
         31 . The method of  claim 1 , comprising separating the (CF 3 ) 2 CHOCH 2 F from the mixture by fractional distillation.  
     
     
         32 . The method of  claim 1 , comprising separating the (CF 3 ) 2 CHOCH 2 F from the mixture by distillation with an inert high boiling solvent having a boiling point above that of sevoflurane.  
     
     
         33 . The method of  claim 32 , wherein the high boiling solvent is an aromatic hydrocarbon.  
     
     
         34 . The method of  claim 33 , wherein the aromatic hydrocarbon is xylene.  
     
     
         35 . The method of  claim 32 , wherein the distillation with the inert high boiling solvent proceeds simultaneously with reacting the mixture.  
     
     
         36 . A method for the preparation of sevoflurane which comprises: 
 (a) providing (CF 3 ) 2 CHOCH 3 ;    (b) contacting the (CF 3 ) 2 CHOCH 3  with chlorine gas;    (c) exposing the mixture to a sufficient amount of light to initiate and sustain an exothermic reaction;    (d) allowing the exothermic reaction to proceed to produce a (CF 3 ) 2 CHOCH 2 Cl intermediate; and    (e) reacting in a liquid mixture the (CF 3 ) 2 CHOCH 2 Cl intermediate with hydrogen fluoride and an amine;    to form (CF 3 ) 2 CHOCH 2 F.    
     
     
         37 . The method of  claim 36 , wherein the (CF 3 ) 2 CHOCH 2 Cl intermediate is reacted with the amine and the hydrogen fluoride by heating.  
     
     
         38 . The method of  claim 36 , wherein the (CF 3 ) 2 CHOCH 2 Cl intermediate is reacted with the amine and the hydrogen fluoride by heating at 40° C. to 80° C.  
     
     
         39 . The method of  claim 36 , wherein the (CF 3 ) 2 CHOCH 2 Cl intermediate is reacted with the amine and the hydrogen fluoride by heating at 55° C. to 65° C.  
     
     
         40 . The method of  claim 36 , wherein the light is ultraviolet light.  
     
     
         41 . The method of  claim 36 , wherein the amine is a tertiary amine.  
     
     
         42 . The method of claim  41 , wherein the tertiary amine is selected from triethyl amine, tripropyl amine, triisopropylamine, tributylamine, dimethyl ethyl amine, di-isopropyl ethyl amine, N-methyl pyrrolidine, or mixtures thereof.

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