Pyrrolidine compounds and process of preparing

Abstract

This invention relates to benzolididene compounds of the formula ##STR1## in which R 2 represents the radical ##STR2## in which R 4 and R 5 are identical or different and denote halogen, cyano, ethinyl, trifluoromethoxy, methylthio, nitro, trifluoromethyl or straight-chain or branched alkyl, alkenyl, alkinyl or alkoxy having up to 4 carbon atoms, and one of the substituents optionally represents hydrogen, or a salt thereof.[...]..Iadd., and A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkoxy having up to 6 carbon atoms or by a group of the formula --NR 6 R 7 or --SO 2 R 8 , in which R 6 and R 7 are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms and R 8 denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl. .Iaddend.

We claim: 
     
       1. A benzylididene compound of the formula ##STR20## in which R 2  represents the radical ##STR21## in which R 4  and R 5  are identical or different and denote halogen, cyano, ethinyl, trifluoromethoxy, methylthio, nitro, trifluoromethyl or straight-chain or branched alkyl, alkenyl, alkinyl or alkoxy having up to 4 carbon atoms, and one of the substituents optionally represents hydrogen, or a salt thereof.[...]..Iadd., and   A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkoxy having up to 6 carbon atoms or by a group of the formula --NR 6  R 7  or --SO 2  R 8 , in which R 6  and R 7  are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms   and   R 8  denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl. .Iaddend.     
     
     
       2. An enantiomerically pure aminocrotonic esters of the formula ##STR22## in which A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkoxy having up to 6 carbon atoms or by a group of the formula --NR 6  R 7  or --SO 2  R 8 , in which R 6  and R 7  are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms   and   R 8  denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl.   
     
     
       3. A process for the preparation of the enantiomerically pure benzylidene compound of formula II according to claim 1, which comprises reacting an aldehyde of formula   R.sup.2 --CHO     in which   R 2  represents the radicals ##STR23## in which R 4  and R 5  are identical or different and denote halogen, cyano, ethinyl, trifluoromethoxy, methylthio, nitro, trifluoromethyl or straight-chain or branched alkyl, alkenyl, alkinyl or alkoxy having up to 4 carbon atoms, and one of the substituents optionally represents hydrogen, with enantiomerically pure acetoacetic ester of the formula ##STR24## in which A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkyl having up to 6 carbon atoms or by a group of the formula --NR 6  R 7  or --SO 2  R 8 , in which   R 6  and R 7  are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms   and   R 8  denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl, in an inert solvent and in the presence of a base and of a carboxylic acid.       
     
     
       4. An enantiomerically pure acetoacetic ester of the formula ##STR25## in which A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkoxy having up to 6 carbon atoms or by a group of the formula --NR 6  R 7  or --SO 2  R 8 , in which R 6  and R 7  are identical of different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms   and   R 8  denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl.   
     
     
       5. A method of preparing a compound according to claim 4, which comprises reacting a compound of the formula ##STR26## in which A represents hydrogen or straight-chain or branched alkyl having up to 8 carbon atoms, or represents phenyl or benzyl which are optionally substituted one to three times by identical or different substituents from the series consisting of hydroxyl, nitro, halogen, cyano, carboxyl, trifluoromethyl, trifluoromethoxy, straight-chain or branched alkoxy having up to 6 carbon atoms or by a group of the formula --NR 6  R 7  or --SO 2  R 8 , in which R 6  and R 7  are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 5 carbon atoms   and   R 8  denotes straight-chain or branched alkyl having up to 4 carbon atoms or phenyl, with a diketene or with the diketene/acetone addition product 2,2,6-trimethyl-1,3-dioxin-4-one in an inert solvent.