Hydroxybenzoyl Chlorides in the Synthesis of Conjugates with Biologically Active Dipeptides

Conjugates of hydroxy- and acetoxybenzoic acids with dipeptides based on 4-aminobutanoic acid and glycine were synthesized through hydroxy(acetoxy)benzoyl chlorides and 4-[hydroxy(acetoxy)benzoylamino]butanoyl chlorides as intermediate products. Acyl chlorides were prepared by treatment of the corresponding acids with oxalyl chloride in the presence of dimethylformamide at a ratio of 1:1.1:0.07 in boiling benzene. The target N-[hydroxy(acetoxy)benzoyl] derivatives of dipeptides were obtained with high yields, and no further purification of the products was necessary. The synthesized compounds were evaluated as potential neuroprotective agents.