- Forward- and reverse-synthesis of piperazinopiperidine amide analogs: A general access to structurally diverse 4-piperazinopiperidine-based CCR5 antagonists
-
Piperazinopiperidine amide analogs are among the most promising CCR5 antagonists. As an effective extension of a previously-reported methodology to synthesize such compounds, forward- and reverse-syntheses were successfully developed in which the convergent synthesis of the piperazinopiperidine nucleus, with a building block of 4-substituent-4-aminopiperidine, served as a common key step. The two-way approach affords a comprehensive access to the piperazinopiperidine templated library with variation on the pharmacophore sites. Thus, a SAR study of our synthesized piperazinopiperidine-based CCR5 antagonists was conducted with respect to the structure and configuration of the substituent on the piperazine ring. The S-configuration of the benzylic-substituent is vital for the CCR5 binding, and the bulky or aryl substituent on the 2-position in the piperazine ring is detrimental to the activity. By using the forward-synthesis approach, the best compound in the chiral piperazine-based CCR5 antagonist series, Sch-D (Vicriviroc), was conveniently synthesized in an excellent yield. The Royal Society of Chemistry.
- Feng, Dong-Zhi,Song, Yan-Li,Jiang, Xiao-Hua,Chen, Li,Long, Ya-Qiu
-
p. 2690 - 2697
(2008/03/12)
-
- An improved synthesis of piperazino-piperidine based CCR5 antagonists with flexible variation on pharmacophore sites
-
An improved and efficient synthetic route towards piperidino-piperazine based CCR5 antagonists was developed. The new approach was flexible for introducing various substituents in the pharmacophore sites via Grignard reagent addition and reductive amination. l-Amino acids were used as a chiral pool to introduce and then induce the desired stereochemistries, meanwhile rendering the variable substitution. The efficient construction of the piperazino-piperidine nucleus was achieved in a highly convergent manner with a key building block of N1-Boc-4-substituent-4-aminopiperidine, exhibiting significant advantages in terms of concise synthetic route and environmental-friendly reagents over the previously described stepwise synthesis, in which a modified Strecker reaction was involved with highly toxic reagents such as diethylaluminum cyanide.
- Jiang, Xiao-Hua,Song, Yan-Li,Feng, Dong-Zhi,Long, Ya-Qiu
-
p. 1281 - 1288
(2007/10/03)
-
- Facile synthesis of 4-substituted-4-aminopiperidine derivatives, the key building block of piperazine-based CCR5 antagonists
-
4-Substituted-4-aminopiperidine is an interesting structural motif found in a number of bioactive compounds. An efficient and convenient method for the synthesis of 4-differently substituted-4-aminopiperidine derivatives was described, employing isonipecotate as a starting material and Curtius rearrangement as a key step. The alkylation of isonipecotate could introduce various substituents at the 4-position of the piperidine ring. With this key building block, we are able to efficiently synthesize piperazino-piperidine based CCR5 antagonist in a highly convergent manner free of using toxic reagents such as diethylaluminum cyanide. The concise synthesis of a potent bioavailable CCR5 antagonist as HIV-1 entry inhibitor, Sch-350634 (1) was accomplished in excellent yield using N′-Boc-4-methyl-4-aminopiperidine 5a as a smart building block. The new methodology provides a facile and practical access to the piperazino-piperidine amide analogs as HIV-1 entry inhibitors.
- Jiang, Xiao-Hua,Song, Yan-Li,Long, Ya-Qiu
-
p. 3675 - 3678
(2007/10/03)
-