N-Bromosuccinimide as an oxidant for the transition-metal-free synthesis of 2-aminobenzoxazoles from benzoxazoles and secondary amines.
A facile and transition-metal-free method was developed through merging the ring opening of benzoxazoles with secondary amines and N-bromosuccinimide (NBS) mediated oxidative cyclization toward the synthesis of 2-aminobenzoxazoles. NBS was selected as a powerful oxidant in the oxidative cyclization of ring-opening amidines to provide the desirable 2-aminobenzoxazoles in excellent yields (up to 94%).
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China. wsun@licp.cas.cn.
Xiaoe
X
Wang
Daqian
D
Xu
Chengxia
C
Miao
Qiaohong
Q
Zhang
Wei
W
Sun
D000586:Amination; D000588:Amines / Q000737:chemistry*; D001583:Benzoxazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D001974:Bromosuccinimide / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D017481:Receptors, Somatostatin / Q000037:antagonists & inhibitors; D028561:Transition Elements / Q000737:chemistry*
D000588:Amines; D001583:Benzoxazoles; D016877:Oxidants; D017481:Receptors, Somatostatin; D028561:Transition Elements; C094573:somatostatin receptor 5; D001974:Bromosuccinimide