Gram-Scale Synthesis of Perdeuterated Paracetamol

Area of Science:

• Materials Science
• Chemistry
• Neutron Scattering

Background:

• Deuterated compounds are crucial for neutron total scattering on disordered materials.
• Existing methods yield small quantities (milligram scale) with limited deuterium incorporation.

Purpose of the Study:

• To develop a multigram-scale synthesis of paracetamol-d9.
• To improve deuterium incorporation for neutron scattering applications.

Main Methods:

• Acid-catalyzed deuteration of 4-aminophenol using microwave irradiation.
• Purification of the intermediate 4-aminophenol-d4 via sublimation.
• Acetylation of the purified intermediate to yield paracetamol-d9.

Main Results:

• Successful multigram synthesis of paracetamol-d9 and related isotopologues.
• Achieved >93% average deuterium incorporation.
• Obtained >10g of final product with minimum 78% deuterium at individual positions.

Conclusions:

• The developed method provides a scalable route to high-purity, perdeuterated paracetamol.
• This facilitates neutron scattering studies requiring large, well-deuterated samples.
• Sublimation is key for purifying unstable intermediates and ensuring product quality.