Ethyl chloroformate → Ethyl 4-[(4-fluorophenyl)(3-pyridinyl)methylene]-1-piperidinecarboxylate
Reaction equation
[C:1](Cl)(=[O:5])[O:2][CH2:3][CH3:4].[F:7][C:8]1[CH:13]=[CH:12][C:11]([C:14](=[C:21]2[CH2:26][CH2:25][N:24](C)[CH2:23][CH2:22]2)[C:15]2[CH:16]=[N:17][CH:18]=[CH:19][CH:20]=2)=[CH:10][CH:9]=1>ClC(Cl)Cl>[F:7][C:8]1[CH:13]=[CH:12][C:11]([C:14]([C:15]2[CH:16]=[N:17][CH:18]=[CH:19][CH:20]=2)=[C:21]2[CH2:22][CH2:23][N:24]([C:1]([O:2][CH2:3][CH3:4])=[O:5])[CH2:25][CH2:26]2)=[CH:10][CH:9]=1Participants
4
Procedure
To a stirred solution of 180 parts of ethyl carbonochloridate in 600 parts of trichloromethane was added dropwise a solution of 110 parts of 3-[(4-fluorophenyl)(1-methyl-4-piperidinylidene)methyl]pyridine in 600 parts of trichloromethane. Upon completion, the whole was heated till reflux and stirring at reflux was continued for 16 hours. The reaction mixture was evaporated. The residue was stirred in water and the whole was alkalized with a sodium hydroxide solution. The product was extracted with 4-methyl-2-pentanone. The extract was dried, filtered and evaporated, yielding 100 parts (75%) of ethyl 4-[(4-fluorophenyl)(3-pyridinyl)methylene]-1-piperidinecarboxylate as a residue (intermediate 20).