5-Nitrobenzofurans

Abstract

The present invention relates to 5-nitrobenzofurans, to a process for preparing 5-nitrobenzofurans, and to 5-nitro-2,3-dihydrobenzofuran-3-ols, to a process for the preparation thereof and to intermediates.

1 . At least one compound of the formula (I),  
       
         
           
           
               
               
           
         
         wherein  
         R 1  is hydrogen or C 1 -C 12 -alkyl, and  
         R 2  are in each case independently of one another: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl), —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 -alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl and  
         n is zero, one, two or three, or in the case where n is two or three it is possible for two adjacent R 2  substituents to be part of a fused ring system which in turn may optionally be substituted by the radicals mentioned above for R 2 ,  
         with the proviso of 2-(n-butyl)-5-nitrobenzofuran being excluded.  
       
     
     
         2 . (canceled)  
     
     
         3 . (canceled)  
     
     
         4 . At least one compound of the formula (III),  
       
         
           
           
               
               
           
         
         wherein R 2  and n have the meaning specified under formula (I) in  claim 1 , and R 1  is n-butyl.  
       
     
     
         5 . 2-(n-Butyl)-5-nitro-3(2H)-benzofuranone.  
     
     
         6 . At least one compound of the formula (V),  
       
         
           
           
               
               
           
         
         wherein  
         R 2  and n have the meaning specified under formula (I) in  claim 1 ,  
         R 1  is n-butyl and  
         R 7  is C 1 -C 12 -alkyl, C 5 -C 25 -arylalkyl, C 4 -C 24 -aryl or C 1 -C 12 -fluoroalkyl.  
       
     
     
         7 . 3-Acetoxy-2-(n-butyl)-benzofuran.  
     
     
         8 . At least one compound of the formula (VII),  
       
         
           
           
               
               
           
         
         wherein R 2  and n have the meaning specified under formula (I) in  claim 1 , R 1  is n-butyl and R 9  and R 10  are independently of one another C 1 -C 12 -alkyl, C 5 -C 25 -arylalkyl or C 4 -C 24 -aryl, and furthermore not more than one R 9  or R 10  radical is hydrogen.  
       
     
     
         9 . At least one compound selected from the group consisting of methyl 2-(1-methoxycarbonylpentoxy)benzoate, ethyl 2-(1-methoxycarbonylpentoxy)benzoate, ethyl 2-(1-ethoxycarbonylpentoxy)benzoate, methyl 2-(1-ethoxycarbonylpentoxy)benzoate, 2-(1-methoxycarbonylpentoxy)benzoic acid, 2-(1-ethoxycarbonylpentoxy)benzoic acid, ethyl 2-(1-carboxypentoxy)benzoate and methyl 2-(1-carboxypentoxy)benzoate.  
     
     
         10 . A process for preparing at least one compound of the formula (I),  
       
         
           
           
               
               
           
         
         wherein  
         R 1  is hydrogen or C 1 -C 12 -alkyl, and R 2  are in each case independently: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl), —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 -alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl and  
         n is zero, one, two or three, or in the case where n is two or three it is possible for two adjacent R 2  substituents to be part of a fused ring system which in turn may optionally be substituted by the radicals mentioned above for R 2 ,  
         wherein the process comprises converting by dehydration  
         at least one compound of the formula (II)  
         
           
             
             
                 
                 
             
           
         
         in which R 1 , R 2  and n have the meaning under formula (I),  
         into compounds of the formula (I).  
       
     
     
         11 . Process according to  claim 10 , characterized in that 2-(n-butyl)-5-nitrobenzofuran is prepared.  
     
     
         12 . Process according to  claim 10 , characterized in that protic acids or hydroxides are employed for the dehydration.  
     
     
         13 - 20 . (canceled)  
     
     
         21 . A process for preparing at least one compound of the formula (II),  
       
         
           
           
               
               
           
         
         wherein R 1  is hydrogen or C 1 -C 12 -alkyl, and  
         R 2  are in each case independently of one another: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl), —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl and  
         n is zero, one, two or three, or in the case where n is two or three it is possible for two adjacent R 2  substituents to be part of a fused ring system which in turn may optionally be substituted by the radicals mentioned above for R 2 ,  
         with the proviso of 2-(n-butyl)-5-nitrobenzofuran being excluded;  
         wherein the process comprises reducing compounds of the formula (III)  
         
           
             
             
                 
                 
             
           
         
         wherein R 1  is hydrogen or C 1 -C 12 -alkyl, and R 2  are in each case independently: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl) —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 -alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl and  
         n is zero, one, two or three, or in the case where n is two or three it is possible for two adjacent R 2  substituents to be part of a fused ring system which in turn may optionally be substituted by the radicals mentioned above for R 2 .  
       
     
     
         22 . A process for preparing at least one compound of the formula (III),  
       
         
           
           
               
               
           
         
         wherein R 1  is n-butyl and R 2  are in each case independently of one another: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl), —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 -alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl  
         wherein the process comprises nitrating compounds of the formula (IV)  
         
           
             
             
                 
                 
             
           
         
         wherein R 1 , R 2  and n have the meanings specified under formula (I).  
         R 1  is hydrogen or C 1 -C 12 -alkyl, and  
         R 2  are in each case independently of one another: fluorine, chlorine, bromine, iodine, C 1 -C 12 -alkyl, C 1 -C 12 -alkoxy, hydroxyl, NR 3 R 4  or CONR 3 R 4 , where R 3  and R 4  are each, independently of one another, hydrogen or C 1 -C 12 -alkyl, or NR 3 R 4  as a whole is a cyclic amino radical having 4 to 12 carbon atoms, COO—(C 1 -C 12 -alkyl), —COO(C 4 -C 24 -aryl), —COO(C 5 -C 25 -arylalkyl), CO(C 1 -C 12 -alkyl), CO(C 4 -C 24 -aryl) or C 1 -C 12 -fluoroalkyl.  
       
     
     
         23 . A process for producing medicaments and physiologically active substances comprising providing the compounds of  claim 1 .  
     
     
         24 . A process for producing medicaments and physiologically active substances comprising providing therefor the compounds of  claim 10 .  
     
     
         25 . A process for treating cardiac arrhythmias comprising administering medicaments and physiologically active substances as recited in  claim 23 .  
     
     
         26 . The process according to  claim 25 , characterized in that the physiologically active substance is dronedarone.