270062-75-4

Upstream product

• 100-14-1 4-nitrobenzyl chloride 
• 5464-78-8 1-(2-methoxyphenyl)piperazine hydrochloride 
• 35386-24-4 1-(2-Methoxyphenyl)piperazine 

Downstream Products

• 70261-78-8 1-(4-methoxyphenyl)-4-[ (4-aminophenyl)-methyl ]piperazine 
• 70261-72-2 4-[[4-[[4-(4-methoxyphenyl)-1-piperazinyl ]-methyl ]phenyl ]amino ]-7-(trifluoromethyl)-quinoline 

Relevant academic research and scientific papers

The Effect of Carboxamide/Sulfonamide Replacement in Arylpiperazinylalkyl Derivatives on Activity to Serotonin and Dopamine Receptors

A series of carboxamide and sulfonamide alkyl (p-xylyl and benzyl) 1-(2-methoxyphenyl)piperazine (o-OMe-PhP) and 1-(2,3-dichlorophenyl)piperazine (2,3-DCPP) analogs were prepared and tested for their affinity to bind to serotonin 5-HT1A/5-HT6/5-HT7 and dopamine D2 receptors. This chemical modification let us explore the impact of the replacement of the carboxamide by the sulfonamide group on the affinity changes. In both the o-OMe-PhP and 2,3-DCPP series, the relative activities of the carboxamides versus sulfonamides toward the 5-HT1A/5-HT6/5-HT7 and D2 receptors show similar trends. Varied or similar activities for particular receptors were found for the carboxamides/sulfonamides with p-xylyl spacer, while of the two classes of carboxamides and sulfonamides examined, benzyl derivatives of the sulfonamides displayed the highest serotoninergic affinity, in particular to the 5-HT7 receptors (Ki 8–85 nM). The Ki values revealed that, irrespective of the carboxamide/sulfonamide zone, both p-xylyl and benzyl derivatives had the highest affinity for the dopamine D2 receptor (i.e., 16 out of 24 compounds investigated have an affinity below 100 nM). A molecular modeling study of carboxamide 9a and sulfonamide 9b showed that their binding effects to each of 5-HT1AR and D2R created binding modes interaction with different conserved receptors residues. Structural similarities of carboxamide 9a in complexes with a 5-HT1AR (9aI) and D2R (9aII) are over 83%, while the respective similarities of sulfonamide 9b structures (9bI/9bII) are only about 40%.

Interaction of arylpiperazines with the dopamine receptor D2 binding site

The docking of several 1-benzyl-4-arylpiperazines to the dopamine receptor (DAR) D2 was examined. The results demonstrated that the interaction of protonated N1 of the piperazine ring with Asp 86 (III.32) and edge-to-face interactions of the aromatic ring of the arylpiperazine part of the ligand with Phe 178 (VI.44), Trp 182 (VI.48) and Tyr 216 (VII.58) of the receptor, represent the major stabilizing forces. Besides, the hydrogen bond acceptor group in position 2 of the phenylpiperazine aromatic ring could build one more hydrogen bond with Trp 182 (VI.48). Bulky substituents in position 4 were not tolerated due to the unfavorable sterical interaction with Phe 178 (VI.44). Substituents in position 2 and 3 were found to be sterically well tolerated. Introduction of electron attractive -NO2 group in position 3 of arylpiperazines decreased, while electron donors (-OMe) and the second aromatic ring (naphthyl) increased the binding affinity comparing to that of the phenylpiperazine 1. This can be explained in terms of favoured edge-to-face interactions in ligands with a high negative electrostatic surface potential (ESP) in the centre of aromatic residue of arylpiperazines. Thus, besides the salt bridges and hydrogen bonds, edge-to-face interactions significantly contribute to arylpiperazine ligands to form complexes with the DAR D2. Phe 178 (VI.44), Trp 182 (VI.48) and Tyr 216 (VII.58) can be considered as a part of the ancillary DAR D2 pocket preserved in most G protein-coupled receptors of the A class and obviously, the arylpiperazine structural motif represents one of the privileged structures that bind to this pocket.

Thin layer chromatography as a tool for reaction optimisation in microwave assisted synthesis

Reaction parameters for the microwave assisted synthesis of N'- substituted arylpiperazines were optimised via their rapid synthesis on thin layer chromatography (TLC) plates.