Some other references on the peroxide oxidation of anthanilic acid from isatin are: Berichte, 57, 2105 (1924); JACS 65, 1802 (1943); and HCA, 9, 578 (1926). Ortho-toluidine is generally made via the reduction of ortho-nitrotoluene, some references on that synthesis are: Proc. K. Acad. Wetensch 11, 248 (1908); Monatsh 31, 745 (1910); Rec. Trav. Chim. 33, 10 (1914); JCS 121, 270 (1922); CA 20, 389 (1926); Bull. Soc. Chim. Belg. 42, 80 (1933); JACS 65, 2426 (1943) & JCS 22, 112 (1944).