Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Racemic Mixtures and the Resolution of Enantiomers

Racemic Mixtures and the Resolution of Enantiomers

A racemic mixture, or racemate, is an equimolar mixture of enantiomers of a molecule that can be separated using their unique interaction with chiral molecules or media. Racemic mixtures are denoted by the (±)- prefix. This ‘optical rotation descriptor’ applies to the whole solution of a racemic mixture rather than a specific stereoisomer. Enantiomers typically have the same physical and chemical properties. Hence, they are not easily separable. However, enantiomers can exhibit...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

<i>H</i>-linear magnetoresistance in NbSe<sub>2</sub> due to impeded cyclotron motion.

Science advances·2026

Same author

Analytical interpretation of hemodynamic data in patients with intracardiac shunts: Role of mathematical modeling.

International journal of cardiology. Congenital heart disease·2026

Same author

How Crystal Size and Number Steer Asymmetric Crystallization.

The journal of physical chemistry letters·2026

Same author

Relationship between falls and physical activity in daily life of people with Parkinson's disease.

Parkinsonism & related disorders·2025

Same author

Deracemization by coupling electrochemically assisted racemization and asymmetric crystallization.

Chemical communications (Cambridge, England)·2025

Same author

(2-Amino-ethan-1-aminium-κ<i>N</i> <sup>2</sup>)tri-chlorido-zinc(II).

IUCrData·2025

Search research articles

Related Experiment Video

Updated: Nov 28, 2025

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs

Published on: May 15, 2019

Combining Incompatible Processes for Deracemization of a Praziquantel Derivative under Flow Conditions.

Giulio Valenti¹, Paul Tinnemans², Iaroslav Baglai³

¹Symeres, Kadijk 3, 9747 AT, Groningen, The Netherlands.

Angewandte Chemie (International Ed. in English)

|November 26, 2020

Summary

A novel method efficiently converts racemates to the (R)-enantiomer of Praziquantel using coupled racemization and crystallization. This process yields high enantiomeric purity for valuable chiral compounds.

Keywords:

chirality flow chemistry heterogeneous catalysis racemization schistosomiasis

More Related Videos

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Published on: April 7, 2023

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

Published on: February 10, 2023

Related Experiment Videos

Last Updated: Nov 28, 2025

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs

Published on: May 15, 2019

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Published on: April 7, 2023

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

Published on: February 10, 2023

Area of Science:

Chemical Engineering
Organic Chemistry
Crystallization Science

Background:

Praziquantel is a crucial drug for treating parasitic worm infections.
Efficient synthesis of enantiomerically pure drugs is vital for pharmaceutical development.
Existing methods for chiral compound synthesis often face challenges with harsh conditions or low yields.

Purpose of the Study:

To develop an efficient deracemization method for producing the (R)-enantiomer of Praziquantel.
To couple incompatible racemization and crystallization processes for enhanced synthesis.
To identify a Praziquantel derivative that crystallizes as a conglomerate.

Main Methods:

A library approach was used to identify a suitable Praziquantel derivative.
Racemization was achieved via reversible hydrogenation over palladium on carbon (Pd/C) at 130°C.
Deracemization involved alternating crystal growth/dissolution steps with temperature cycling (5-15°C) in a flow system.

Main Results:

A Praziquantel derivative crystallizing as a conglomerate was identified.
The coupled flow system successfully combined racemization and crystallization.
Complete deracemization of the solid phase yielded the desired (R)-enantiomer with 98% enantiomeric excess (ee).

Conclusions:

An unprecedented deracemization method using decoupled crystallization and racemization was established.
This approach offers a practical and efficient route to enantiomerically pure (R)-Praziquantel.
The method opens new avenues for synthesizing essential chiral building blocks requiring harsh racemization conditions.