Aromatization of aliphatic compounds. VII. Benzofuranones,indoles and oxindoles

2(4H)-5,6-Dihydrobenzofuranones 3 gave, when treated with pyridine hydrochloride at 200°, the corresponding arylacetic acids 1 in good yields, whereas the aza analogues, the tetrahydrooxindoles 6 gave indoles in poor yields. The oxidation products of 3 ( 11 and 13 ) and of 6 ( 12, 14 and 15 ) gave, with the same reagent, benzofuranones and oxindoles, respectively, both in good yields.