Synthesis of Novel Symmetrical and Unsymmetrical o-Phthalic Acid Diamides

Phthalic anhydride was treated with secondary amines in acetic acid yielding 2-(diethyl (or) 4-alkylpiperazine or morpholine-1-carbonyl) benzoic acids. The latter were reacted, again, with secondary amines and arylamines by using the coupling reagent HATU and Et3N as a base in DMF giving the novel symmetrical o-phthalic acid diamides [ o-R 1 R 1 NCOC 6 H 4 CONR 1 R 1 ] , unsymmetrical o-phthalic acid diamides [ o-R 1 R 1 NCOC 6 H 4 CONR 1 R 2 ] , and primary amidic-secondary amidic containing unsymmetrical o-phthalic acid diamides [ o-R 1 R 1 NCOC 6 H 4 CONHAr ] , respectively.