102260-58-2Relevant articles and documents
The Bromination of Salicylate Anions. Evidence for the Participation of the Ortho Carboxylate Group
Tee, Oswald S.,Iyengar, N. Rani
, p. 4468 - 4473 (1985)
Salicylate monoanions show reduced selectivity toward bromine in aqueous solution when compared to similarly substituted phenols.In particular, 5-substituted salicylate ions show ρ+ = -2.69 whereas for para-substituted phenols ρ+ = -5.21.From this and other evidence it is argued that bromine attack on such ions may involve proton transfer from the hydroxyl group to the o-carboxylate to which it is hydrogen bonded. 5-Methylsalicyclic acid (8a) forms, in part, an unstable cyclohexadienone (13) resulting from ipso bromine attack.The breakdown of 13 shows intramolecular catalysis by the o-COOH group, which has an effective molarity of 58 M.The microscopic reverse reaction of bromine on the anion 8a must, therefore, involve the o-CO2- group, as suggested above.Implications with respect to the activating effect of hydroxyl groups on cation-forming reactions are discussed.
