反应详情

In Scheme 4a, a 2-aminophenol, 2-aminothiophenol or 2-aminoaniline derivative 4a is heated with an appropriately substituted 4-aminobenzoic acid 4b in polyphosphoric acid at about 170° C. to 200° C. for 4–10 hr, preferably 190° C. for 6 hr, to yield the corresponding 4-benzoxazol-2-yl-phenylamine, 4-benzothiazol-2-yl-phenylamine, or 4-benzimidazol-2-yl-phenylamine derivatives 1e4.