Microwave-Assisted Synthesis of (±)-Mandelic Acid-𝑑₅, Optical Resolution, and Absolute Configuration Determination

Scheme 1

Synthesis of (±)-2-hydroxy-2-(D₅)phenyl acetic acid [(±)-MA-𝐝_𝟓, (±)-3]. Reagents and conditions: (i) 2,2-dichloroacetyl chloride, AlCl₃, CH₂Cl₂, microwave irradiation, 70°C, 8 min; (ii) 1 M NaOH, H₂O, microwave irradiation, 110°C, 11 min; 82% overall yield.