[C:1]([NH:4][C:5]1[C:13]([OH:14])=[CH:12][CH:11]=[C:7]([C:8]([OH:10])=O)[C:6]=1[C:15]([OH:17])=[O:16])(=O)[CH3:2].CC1OC2C=CC(C(O)=O)=C(C(O)=O)C=2N=1>C(OC(=O)C)(=O)C.S(=O)(=O)(O)O>[CH3:2][C:1]1[O:14][C:13]2[CH:12]=[CH:11][C:7]3[C:8]([O:17][C:15](=[O:16])[C:6]=3[C:5]=2[N:4]=1)=[O:10]A 4:1 mixture of 3-acetamido-4-hydroxyphthalic acid and 2-methyl-4,5-benzoxazoledicarboxylic acid in acetic anhydride and concentrated sulfuric acid (0.10 mL) is stirred for 18 hours at 110° C., cooled and filtered. The white solid filter cake is air dried to give the title product, 5.39 g (77.1%), identified by NMR and IR spectral analyses.
Wird geladen…