Prepd from salicylic acid and Br2: Earle, Jackson, J. Am. Chem. Soc. 28, 111 (1906); Robertson, J. Chem. Soc. 82, 1481 (1902); and HOBr: Leulier, Pinet, Bull. Soc. Chim. Fr. [4] 41, 1362 (1927).