Synthesis
General procedure for the synthesis of 2-methyl-5-chlorobenzoxazole from the compound (CAS: 1019187-32-6) as starting material: to a stirring solution of o-hydroxyaryl N-H ketoimine 1 (1 mmol) in solvent (2 mL) were added sequentially additives (if applicable, 0.2-1.0 mmol) and iodobenzene diacetate (PhI(OAc)2, 1.1-2.0 mmol). The reaction mixture was stirred at room temperature for 30 min before the solvent was removed by distillation under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: pentane/ethyl acetate, 30-100:1, v/v) to afford the target product 2-methyl-5-chlorobenzoxazole.
References
[1] Tetrahedron, 2015, vol. 71, # 4, p. 700 - 708
[2] Patent: CN103951631, 2017, B. Location in patent: Paragraph 0044; 0046; 0047