US2005085638A1PendingUtilityA1

Process for producing dioxolane nucleoside analogues

Assignee: SHIRE BIOCHEM INCPriority: Jan 25, 2002Filed: Jan 23, 2003Published: Apr 21, 2005
Est. expiryJan 25, 2022(expired)· nominal 20-yr term from priority
C07D 473/16C07D 473/00C07D 473/32C07D 405/04C07D 317/34
43
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Claims

Abstract

The present invention relates to a process conducted in a single reaction vessel for producing a dioxolane nucleoside analogue of formula I or a pharmaceutically acceptable salt thereof; the process comprising the steps of adding a Lewis acid, a silylating agent and a non-silylated purine or pyrimidine base or an analogue thereof to a dioxolane of formula II. The invention also provides a process for producing a dioxolane compound of formula III; by reacting a dioxolane compound of formula IV in a suitable solvent in the presence of DIB and I 2 , using a suitable source of energy.

Claims

exact text as granted — not AI-modified
1 . A process conducted in a single reaction vessel for producing a dioxolane nucleoside analogue of formula I or a pharmaceutically acceptable salt thereof;  
       
         
           
           
               
               
           
         
         the process comprising the steps of adding:  
         a Lewis acid;  
         a silylating agent; and  
         a non-silylated purine or pyrimidine base or an analogue thereof;  
         to a dioxolane of formula II in a suitable solvent;  
         
           
             
             
                 
                 
             
           
         
         wherein;  
         R 1  is a hydroxyl protecting group;  
         R 2  is a purine or pyrimidine base or an analogue thereof;  
         L is a leaving group; and wherein said process is conducted at a suitable temperature.  
       
     
     
         2 . The process according to  claim 1 , wherein the Lewis acid is TMSI.  
     
     
         3 . The process according to  claim 1 , wherein L is acetoxy, benzoyloxy or iodide.  
     
     
         4 . The process according to  claim 1 , wherein L is acetoxy.  
     
     
         5 . The process according to  claim 1 , wherein R 1  is C 1-6  alkyl, C 6-12  aryl, C 6-12  arylalkyl, CO—C 1-6  alkyl, CO—C 1-6  alkoxy, CO—C 6-12  aryloxy, or CO—C 6-12  arylalkyl.  
     
     
         6 . The process according to  claim 1 , wherein R 1  is acetyl, pivaloyl, benzoyl or benzyl.  
     
     
         7 . The process according to  claim 1 , wherein R 1  is benzoyl.  
     
     
         8 . The process according to  claim 1 , wherein the suitable temperature is about −78° C. or warmer.  
     
     
         9 . The process according to  claim 8 , wherein the suitable temperature is about −15° C. or warmer.  
     
     
         10 . The process according to  claim 8 , wherein the suitable temperature is about room temperature.  
     
     
         11 . The process according to  claim 1 , wherein the Lewis acid is TMSI, and wherein said Lewis acid is used in a molar ratio of about 1.0 equivalent to about 2.0 equivalents with respect to the dioxolane of formula II.  
     
     
         12 . The process according to  claim 11 , wherein TMSI is used in a molar ratio of about 1.0 equivalent to about 1.5 equivalents with respect to the dioxolane of formula II.  
     
     
         13 . The process according to  claim 11 , wherein TMSI is used in a molar ratio of about 1.0 equivalent to about 1.2 equivalents with respect to the dioxolane of formula II.  
     
     
         14 . The process according to  claim 2 , wherein said process comprises the steps of: 
 a) first adding TMSI to a solution of the dioxolane of formula II and allowing the resulting mixture to react for a suitable period of time; and    b) adding the silylating agent and the purine or pyrimidine base R 2  to the mixture resulting from step a).    
     
     
         15 . The process according to  claim 1 , wherein the silylating agent is chosen from HMDS, bis(trimethylsilyl)acetamide, TMSI, trimethylsilyl chloride, tButyl-dimethylsilyl trifluoromethanesulfonate or trimethylsilyl trifluoromethanesulfonate.  
     
     
         16 . The process according to  claim 1 , wherein the silylating agent is HMDS.  
     
     
         17 . The process according to  claim 1 , wherein the silylating agent is used in a molar ratio of about 1.0 equivalent to about 5.0 equivalents with respect to the purine or pyrimidine base R 2 .  
     
     
         18 . The process according to  claim 1 , wherein the silylating agent is used in a molar ratio of about 1.0 equivalent to about 2.5 equivalents with respect to the purine or pyrimidine base R 2 .  
     
     
         19 . The process according to  claim 1 , wherein the silylating agent is used in a molar ratio of about 1.0 equivalent to about 1.5 equivalents with respect to the purine or pyrimidine base R 2 .  
     
     
         20 . The process according to  claim 1 , wherein R 2  is chosen from:  
       
         
           
           
               
               
           
         
         wherein;  
         R 3  is H, C 1-6  alkyl, C 1-6  acyl or CO—R 9 ;  
         R 4  and R 5  are each, independently, H, C 1-6  alkyl, bromide, chloride, fluoride, iodide or CF 3 ;  
         R 6 , R 7  and R 8  are each, independently, H, bromide, chloride, fluoride, iodide, amino, hydroxyl or C 3-6  cycloalkylamino, and  
         R 9  is H or C 1-6  alkyl.  
       
     
     
         21 . The process according to  claim 20 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         22 . The process according to  claim 1 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         23 . The process according to  claim 1 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         24 . The process according to  claim 1 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         25 . A process for producing a dioxolane compound of formula III:  
       
         
           
           
               
               
           
         
         the process comprising the step of reacting a dioxolane compound of formula IV in a suitable solvent;  
         
           
             
             
                 
                 
             
           
         
         in the presence of DIB and I 2 , wherein said process is conducted using a suitable source of energy; and wherein R 10  is an hydroxyl protecting group.  
       
     
     
         26 . The process according to  claim 25 , wherein the dioxolane compound of formula IV is added to a mixture of DIB and I 2  over a suitable period of time.  
     
     
         27 . The process according to  claim 25 , wherein the dioxolane compound of formula IV is added to a mixture of DIB, I 2  and acetic acid over a suitable period of time.  
     
     
         28 . The process according to  claim 25 , wherein R 10  is C 1-6  alkyl, C 6-12  aryl, C 6-12  arylalkyl, CO—C 1-6  alkyl, alkoxy, CO—C 6-12  aryloxy, or CO—C 6-12  arylalkyl.  
     
     
         29 . The process according to  claim 28 , wherein R 10  is acetyl, pivaloyl, benzoyl or benzyl.  
     
     
         30 . The process according to  claim 28 , wherein R 10  is benzoyl.  
     
     
         31 . The process according to  claim 25 , wherein the suitable solvent is toluene or dichloromethane.  
     
     
         32 . The process according to  claim 31 , wherein the suitable solvent is dichloromethane.  
     
     
         33 . The process according to  claim 25 , wherein DIB is used in a molar ratio of about 1.0 equivalent to about 2.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         34 . The process according to  claim 33 , wherein DIB is used in a molar ratio of about 1.1 equivalent to about 1.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         35 . The process according to  claim 25 , wherein I 2  is used in a molar ratio of about 0.1 equivalent to about 1.0 equivalent with respect to the dioxolane compound of formula III.  
     
     
         36 . The process according to  claim 35 , wherein I 2  is used in a molar ratio of about 0.3 equivalent to about 0.5 equivalent with respect to the dioxolane compound of formula III.  
     
     
         37 . The process according to  claim 25 , wherein the suitable source of energy is light.  
     
     
         38 . The process according to  claim 37 , wherein the suitable source of energy is tungsten lamp light.  
     
     
         39 . The process according to  claim 37 , wherein the suitable source of energy is daylight.  
     
     
         40 . The process according to  claim 1 , wherein the suitable source of energy is heat.  
     
     
         41 . The process according to  claim 1 , further comprising the step of removing the protecting group R 1  to produce a compound of formula Ia or a pharmaceutically acceptable salt thereof.  
       
         
           
           
               
               
           
         
       
     
     
         42 . A process according to  claim 1 , comprising: 
 a) first adding said Lewis acid to a solution of the dioxolane of formula II in said solvent, and allowing the resulting mixture to react for a suitable period of time; and    b) thereafter adding said silylating agent and the purine or pyrimidine base R 2  to said mixture resulting.    
     
     
         43 . A process according to  claim 2 , wherein L is acetoxy, benzoyloxy or iodide.  
     
     
         44 . A process according to  claim 2 , wherein L is acetoxy.  
     
     
         45 . A process according to  claim 2 , wherein R 1  is acetyl, pivaloyl, benzoyl or benzyl.  
     
     
         46 . A process according to  claim 2 , wherein R 1  is benzoyl.  
     
     
         47 . A process according to  claim 2 , wherein the silylating agent HMDS, bis(trimethylsilyl)acetamide, TMSI, trimethylsilyl chloride, tButyl-dimethylsilyl trifluoromethanesulfonate or trimethylsilyl trifluoromethanesulfonate.  
     
     
         48 . A process according to  claim 2 , wherein the silylating agent is HMDS.  
     
     
         49 . A process according to  claim 2 , wherein R 2  is:  
       
         
           
           
               
               
           
         
         wherein;  
         R 3  is H, C 1-6  alkyl, C 1-6  acyl and CO—R 9 ;  
         R 4  and R 5  are each, independently, H, C 1-6  alkyl, bromide, chloride, fluoride, iodide or CF 3 ;  
         R 6 , R 7  and R 8  are each, independently, H, bromide, chloride, fluoride, iodide, amino, hydroxyl or C 3-6  cycloalkylamino; and  
         R 9  is H or C 1-6  alkyl.  
       
     
     
         50 . A process according to  claim 2 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         51 . A process according to  claim 2 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         52 . A process according to  claim 2 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         53 . A process according to  claim 2 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         54 . A process conducted in a single reaction vessel for producing a dioxolane nucleoside analogue of formula I or a pharmaceutically acceptable salt thereof;  
       
         
           
           
               
               
           
         
         the process comprising adding:  
         a Lewis acid, wherein said Lewis acid is TMSI;  
         a silylating agent selected from HMDS, bis(trimethylsilyl)acetamide, TMSI, trimethylsilyl chloride, tButyl-dimethylsilyl trifluoromethanesulfonate and trimethylsilyl trifluoromethanesulfonate; and  
         a non-silylated purine or pyrimidine base or an analogue thereof;  
         to a dioxolane of formula II in a suitable solvent;  
         
           
             
             
                 
                 
             
           
         
         wherein;  
         R 1  is a hydroxyl protecting group selected from acetyl, pivaloyl, benzoyl and benzyl;  
         R 2  is a purine or pyrimidine base or an analogue thereof;  
         L is a leaving group selected from acetoxy, benzoyloxy and iodide;  
         wherein said process is conducted at a suitable temperature.  
       
     
     
         55 . A process according to  claim 54 , wherein R 2  is chosen from:  
       
         
           
           
               
               
           
         
         wherein;  
         R 3  is H, C 1-6  alkyl, C 1-6  acyl or CO—R 9 ;  
         R 4  and R 5  are each, independently, H, C 1-6  alkyl, bromide, chloride, fluoride, iodide or CF 3 ;  
         R 6 , R 7  and R 8  are each independently H, bromide, chloride, fluoride, iodide, amino, hydroxyl or C 3-6  cycloalkylamino; and  
         R 9  is H or C 1-6  alkyl.  
       
     
     
         56 . A process according to  claim 54 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         57 . A process according to  claim 54 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         58 . A process according to  claim 54 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         59 . A process according to  claim 54 , wherein R 2  is:  
       
         
           
           
               
               
           
         
       
     
     
         60 . A process according to  claim 54 , wherein L is acetoxy.  
     
     
         61 . A process according to  claim 54 , wherein R 1  is benzoyl.  
     
     
         62 . A process according to  claim 54 , wherein the silylating agent is HMDS.  
     
     
         63 . A process according to  claim 54 , wherein said process comprises: 
 first adding TMSI to a solution of the dioxolane of formula II and allowing the resulting mixture to react for a suitable period of time; and    adding the silylating agent and the purine or pyrimidine base R 2  to the mixture resulting from step a).    
     
     
         64 . A process for producing a dioxolane compound of formula III:  
       
         
           
           
               
               
           
         
         the process comprising reacting a dioxolane compound of formula IV in a suitable solvent;  
         
           
             
             
                 
                 
             
           
         
         in the presence of DIB and I 2 , wherein the dioxolane compound of formula IV is added to a mixture of DIB and I 2 ;  
         R 10  is an hydroxyl protecting group chosen from acetyl, pivaloyl, benzoyl or benzyl;  
         said process is conducted using a suitable source of energy.  
       
     
     
         65 . A process according to  claim 64 , wherein DIB is used in a molar ratio of about 1.0 equivalent to about 2.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         66 . A process according to  claim 64 , wherein DIB is used in a molar ratio of about 1.1 equivalent to about 1.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         67 . A process according to  claim 64 , wherein I 2  is used in a molar ratio of about 0.1 equivalent to about 1.0 equivalent with respect to the dioxolane compound of formula III.  
     
     
         68 . A process according to  claim 64 , wherein I 2  is used in a molar ratio of about 0.3 equivalent to about 0.5 equivalent with respect to the dioxolane compound of formula III.  
     
     
         69 . A process for producing a dioxolane compound of formula III: 
 the process comprising reacting a dioxolane compound of formula IV in a suitable solvent;                          in the presence of DIB and I 2 , wherein the dioxolane compound of formula IV is added to a mixture of DIB, I 2  and acetic acid;    R 10  is an hydroxyl protecting group chosen from acetyl, pivaloyl, benzoyl or benzyl;    said process is conducted using a suitable source of energy.    
     
     
         70 . A process according to  claim 69 , wherein DIB is used in a molar ratio of about 1.0 equivalent to about 2.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         71 . A process according to  claim 69 , wherein DIB is used in a molar ratio of about 1.1 equivalent to about 1.5 equivalents with respect to the dioxolane compound of formula III.  
     
     
         72 . A process according to  claim 69 , wherein I 2  is used in a molar ratio of about 0.1 equivalent to about 1.0 equivalent with respect to the dioxolane compound of formula III.  
     
     
         73 . A process according to  claim 69 , wherein I 2  is used in a molar ratio of about 0.3 equivalent to about 0.5 equivalent with respect to the dioxolane compound of formula III.

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