Butyl piperazine

A mixture of 65 parts 1 -[4,4-di-(4-fluoro-phenvl)butyl] -piperazine, 4.33 parts N-(2-chloro-acetyl)-2,6-dimethyl-aniline, 3.2 parts sodium carbonate, a few crystals of potassium iodide in 200 parts 4-methyl-2-pentanone is stirred and refluxed for 70 hours. After cooling there are added 70 parts water. The organic layer is separated, dried over potassium carbonate, filtered and evaporated. The oily residue is dissolved in 80 parts diisopropyl-ether and the solution is filtered hot. After cooling the filtrate at 0°C, the formed solid is filtered off and recystallized from 80 parts ether, yielding 1-[4,4-di-(4-fluoro-phenyl)butyl] -4-[(2,6-dimethyl-anilino-carbonvl)-mathyl] -piperazine MP 159°Cto 161°C. 

Chemical Name 1-(4-Fluorophenvl)-4-[3-(3-pvridoyl)amino] butyl-piperazine Common Name —... 

To assist with the MS/MS structure identification, the gross substructure of buspirone is categorized into profile groups (Kerns et al., 1995). Profile groups directly correlate specific product ions and neutral losses with the presence, absence, substitution, and molecular connectivity (Lee et al., 1996) of specific buspirone substructures and their modifications. The profile groups of buspirone are identified with abbreviations that correspond to the three specific substructures azaspirone decane dione (A), butyl piperazine (B), and pyrimidine (P). Substituted substructures are designated with a subscript ( ), and a dash (-) denotes substructure connectivity. Thus, the buspirone molecule is represented by A-B-P. The As-B-P designation... 

A stirred mixture of 9.9 g (0.03 mole) of l-[4,4-(di-p-fluorophenyl)butyl]piperazine, 5,0 g (0,03 mole) of phenyl N-ethylcarbamate, 6,6 g of potassium carbonate and 100 ml of toluene was heated at reflux for 45 minutes. The mixture was filtered and the solvent was removed. The residual oil was dissolved in ethanol-ether and the hydrochloride was precipitated with hydrogen chloride in ethanol. The solid was collected by filtration and recrystallized from 2-butanone-isopropanol 4 1 to give 6.8 g of N -ethyl-4-[4,4-(di-p-fluorophenyl)butyl]-l-piperazinecarboxamide hydrochloride. Melting point 177-178°C. 

The concept can be illustrated by the identification of the metabolites of the anxiolytic drag buspirone [1, 12]. Buspirone (Figure 10.2b) is considered as a combination of three subgroups the azaspirone decane dione (A), the butyl piperazine (B), and pyrimidine (P). Whereas buspirone itself is annotated at A-B-P, a metabolite with a substitution in the pyrimidine ring can be indicated as A-B-P. It was found that in buspirone the azaspirone decane dione and the pyrimidine part of the molecule are prone to (multiple) substitution, such as hydroxylation, hydroxylation and methoxylation, and glucuronidation. The loss of the complete substructure is also observed. In this way, a total number of 26 buspirone metabolites were identified and categorized. 

C,aH I(a0a Iir-[i3-(3-Nitro-benzoyloxy)- methyl-butyl]-piperazin.N -carbon< siure-athyleeter 23 II9. 

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