Automated pH Controlled Addition Maximises Reaction Yield

A new applications bulletin from Radleys describes how a leading agrochemical research laboratory employed the Lara™ Controlled Laboratory Reactor (CLR) to perform a difficult acid chloride coupling reaction using pH controlled addition.

In the described reaction - acid chloride is automatically fed over a three-hour period into the Lara CLR together with simultaneous sodium hydroxide addition to control the pH in the region of 6.5. The coupling of the acid chloride to the sodium salt of an oxy anion is a biphasic reaction in which the temperature has to be maintained at 10ºC to maximise yield of the final ester product. Efficient stirring of the coupling reaction is essential as the product forms as a thick slurry.

The experimental data demonstrates that the Lara CLR was well suited for automating chemistry of this complex nature where pH control, reaction viscosity and isothermal temperature control were all challenges to maximising yield. With minimal training the users were quickly able to set up the system, get the unit running and reproducibly perform the acid coupling reaction to generate high yields of the ester product.

Lara is a flexible, modular CLR unit which enables rapid interchange of glass vessels from 100ml to 10 litre and the integration of third party devices such as circulators, pumps, balances, pH meters, syringe pumps etc making it the idea process development tool. Lara’s intuitive, easy-to-use; drag-and-drop software allows full control and data logging of all devices and parameters.

A copy of the technical bulletin (TDS05S) can be downloaded from www.lara-clr.com.