A Convenient Procedure for Parallel Ester Hydrolysis

Abstract

The treatment of alkyl esters with barium hydroxide ­octahydrate in methanol followed by protonation with anhydrous hydrogen chloride affords carboxylic acids. The procedure does not require aqueous workup and is particularly suitable for parallel ­synthesis applications.

Key words

ester hydrolysis - deprotection - parallel synthesis - ­barium hydroxide octahydrate - 9-chloroacridine

References

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7

Typical Procedure: A solution of ethyl salicylate (0.161 g, 0.968 mmol) in MeOH (10 mL) was treated with BaOH·8H₂O (0.458 g, 1.45 mmol, 1.5 equiv) and heated to 80 °C for 2 h. Solvent was removed in vacuo, followed by the addition of HCl (1 M in Et₂O) (10 mL) and MgSO₄, and the mixture was filtered, and concentrated to afford salicylic acid (0.115 g, 87%).