Nikzad Nikbin

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

Summary This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of recent years.

A modular flow reactor for performing Curtius rearrangements as a continuous flow process

The use of a mesofluidic flow reactor is described for performing Curtius rearrangement reactions of carboxylic acids in the presence of diphenylphosphoryl azide and trapping of the intermediate isocyanates with various nucleophiles.

Azide monoliths as convenient flow reactors for efficient Curtius rearrangement reactions

The preparation and use of an azide-containing monolithic reactor is described for use in a flow chemistry device and in particular for conducting Curtius rearrangement reactions via acid chloride inputs.

Flow chemistry synthesis of zolpidem, alpidem and other GABAA agonists and their biological evaluation through the use of in-line frontal affinity chromatography

The flow of information between chemical and biological research can present a bottleneck in pharmaceutical research. Tools that bridge these disciplines and aid information exchange have therefore clear value. Over the last few years, both synthetic chemistry and biological screening have benefited from automation, and a seamless chemistry–biology interface is now possible. We report here on the use of flow processes to perform synthesis and biological evaluation in an integrated manner. As proof of concept, a flow synthesis of a series of imidazo[1,2-a]pyridines, including zolpidem and alpidem, was developed and connected to a Frontal Affinity Chromatography screening assay to investigate their interaction with Human Serum Albumin (HSA).

Flow synthesis of organic azides and the multistep synthesis of imines and amines using a new monolithic triphenylphosphine reagent

Here we describe general flow processes for the synthesis of alkyl and aryl azides, and the development of a new monolithic triphenylphosphine reagent, which provides a convenient format for the use of this versatile reagent in flow. The utility of these new tools was demonstrated by their application to a flow Staudinger aza-Wittig reaction sequence. Finally, a multistep aza-Wittig, reduction and purification flow process was designed, allowing access to amine products in an automated fashion.

A Machine‐Assisted Flow Synthesis of SR48692: A Probe for the Investigation of Neurotensin Receptor‐1

Here we report the direct comparison of a conventional batch mode synthesis of Meclinertant (SR48692, 1), a neurotensin receptor-1 antagonist, with its machine-assisted flow chemistry alternative. By using these enabling tools, combined with solid-supported reagents and scavengers, many process advantages were observed. Care, however, must be taken not to convert these techniques into expensive solutions to problems that do not exist.

A "catch-react-release" method for the flow synthesis of 2-aminopyrimidines and preparation of the Imatinib base.

The development of a monolith-supported synthetic procedure is reported, taking advantage of flow processing and the superior flow characteristics of monolithic reagents over gel-phase beads, to allow facile access to an important family of 2-aminopyrimidine derivatives. The process has been successfully applied to a key precursor on route to Imatinib (Ar = 3-pyridyl, R(1) = 2-methyl-5-nitrobenzyl, R(2) = H).

Machine-assisted synthesis of modulators of the histone reader BRD9 using flow methods of chemistry and frontal affinity chromatography

A combination of conventional organic synthesis, remotely monitored flow synthesis and bioassay platforms, were used for the evaluation of novel inhibitors targeting bromodomains outside the well-studied bromodomain and extra terminal (BET) family, here exemplified by activity measurements on the bromodomain of BRD9 protein, a component of some tissue-specific SWi/SNF chromatin remodelling complexes. The Frontal Affinity Chromatography combined with Mass Spectrometry (FAC-MS) method proved to be reliable and results correlated well with an independent thermal shift assay.

Promiscuous targeting of bromodomains by bromosporine identifies BET proteins as master regulators of primary transcription response in leukemia

BET bromodomains are unique targeting modules that mediate primary transcription response. Bromodomains (BRDs) have emerged as compelling targets for cancer therapy. The development of selective and potent BET (bromo and extra-terminal) inhibitors and their significant activity in diverse tumor models have rapidly translated into clinical studies and have motivated drug development efforts targeting non-BET BRDs. However, the complex multidomain/subunit architecture of BRD protein complexes complicates predictions of the consequences of their pharmacological targeting. To address this issue, we developed a promiscuous BRD inhibitor [bromosporine (BSP)] that broadly targets BRDs (including BETs) with nanomolar affinity, creating a tool for the identification of cellular processes and diseases where BRDs have a regulatory function. As a proof of principle, we studied the effects of BSP on leukemic cell lines known to be sensitive to BET inhibition and found, as expected, strong antiproliferative activity. Comparison of the modulation of transcriptional profiles by BSP after a short exposure to the inhibitor resulted in a BET inhibitor signature but no significant additional changes in transcription that could account for inhibition of other BRDs. Thus, nonselective targeting of BRDs identified BETs, but not other BRDs, as master regulators of context-dependent primary transcription response.