N-tert-butoxycarbonyl-2-pyrrolidinones and production method thereof

Abstract

N-tert-butoxycarbonyl-2-pyrrolidinones represented by the following formula (1). In the formula (1), R1, R2, R3, R4, R5 and R6 independently represent a hydrogen atom, a halogen atom, a cyano group, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, which may have a substituent, a linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, which may have a substituent, or the like, R1 and R2 may be linked to form a >C═O group along with the carbon atom to which both are attached, R3 and R4 may be linked to form a >C═O group along with the carbon atom to which both are attached, R5 and R6 may be linked to form a >C═O group along with the carbon atom to which both are attached, or any two among R1, R2, R3, R4, R5 and R6 may be linked to form a polymethylene group having 1 to 4 carbon atoms which may have a substituent.

1 . N-tert-butoxycarbonyl-2-pyrrolidinones of the following formula (1): 
     
       
         
         
             
             
         
       
     
     [wherein, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  represent each independently a hydrogen atom, halogen atom, cyano group, optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, optionally substituted linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted amino group, —OR a  group, or —SR b  group, R a  and R b  represent each independently a hydrogen atom, alkylcarbonyl group having 2 to 10 carbon atoms, arylcarbonyl group having 7 to 20 carbon atoms, aralkyl group having 7 to 20 carbon atoms, alkoxyalkyl group having 2 to 10 carbon atoms, trialkylsilyl group having 3 to 10 carbon atoms, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms,
 alternatively, R 1  and R 2  may be connected to form a >C═O group together with a carbon atom to which they are connected, R 3  and R 4  may be connected to form a >C═O group together with a carbon atom to which they are connected, R 5  and R 6  may be connected to form a >C═O group together with a carbon atom to which they are connected, 
 any two of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  may be connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms, one or no-mutually-adjacent two methylene groups constituting the polymethylene group may be substituted by an oxygen atom, one or two ethylene groups constituting the polymethylene group may be substituted by a vinylene group, no-mutually-adjacent two methylene groups constituting the polymethylene group may be mutually connected via an oxygen atom, methylene group, ethylene group or vinylene group.]. 
 
   
   
       2 . The N-tert-butoxycarbonyl-2-pyrrolidinones according to  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  in the formula (1) represent each independently a hydrogen atom or an optionally substituted linear or branched alkyl group having 1 to 3 carbon atoms, alternatively, any two of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms. 
   
   
       3 . The N-tert-butoxycarbonyl-2-pyrrolidinones according to  claim 1 , wherein R 1 , R 2 , R 4  and R 6  in the formula (1) represent a hydrogen atom, and R 3  and R 5  are connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms. 
   
   
       4 . 3-tert-butoxycarbonyl-6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2-one. 
   
   
       5 . (1R,5S)-3-tert-butoxycarbonyl-6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2-one. 
   
   
       6 . A method of producing N-tert-butoxycarbonyl-2-pyrrolidinones, comprising reacting 2-pyrrolidinones of the following formula (2): 
     
       
         
         
             
             
         
       
     
     [wherein, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  represent the same meanings as described above.] with di-tert-butyl dicarbonate in an aromatic solvent, thereby producing N-tert-butoxycarbonyl-2-pyrrolidinones of the following formula (1): 
     
       
         
         
             
             
         
       
     
     (wherein, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  represent the same meanings as described above.). 
   
   
       7 . The production method according to  claim 6 , wherein the reaction is carried out in the presence of a base in an aromatic solvent. 
   
   
       8 . The production method according to  claim 6 , wherein the aromatic solvent is an aromatic hydrocarbon solvent. 
   
   
       9 . The production method according to  claim 8 , wherein the aromatic hydrocarbon solvent is toluene. 
   
   
       10 . The production method according to  claim 6 , wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  in the formulae (1) and (2) represent each independently a hydrogen atom or an optionally substituted linear or branched alkyl group having 1 to 3 carbon atoms, alternatively, any two of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms. 
   
   
       11 . The production method according to  claim 6 , wherein R 1 , R 2 , R 4  and R 6  in the formulae (1) and (2) represent a hydrogen atom, and R 3  and R 5  are connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms. 
   
   
       12 . The production method according to  claim 6 , wherein R 1 , R 2 , R 4  and R 5  in the formulae (1) and (2) represent a hydrogen atom, and R 3  and R 5  are connected to form a (CH 3 ) 2 C<group.