Tertiary Amines as Temporary Masked Secondary Amines: A Direct Access to 5-Dialkylamino-1,2,4-oxadiazoles from 1,2,4-Oxadiazol-5(4H)-ones
摘要:
A novel strategy utilizing tertiary amines as temporary masked secondary amines to synthesize 5-dialkylamino 1,2,4-oxadiazoles via Ph3P-I2 mediated amination of 1,2,4-oxadiazol-5(4H)-ones was developed. A one-step N-dealkylative functionalization of tertiary amines with the 1,2,4-oxadiazole ring enables a convenient access to diverse 5-amino-1,2,4-oxadiazoles. Additionally, orthogonally functionalized piperazine derivatives can be effectively constructed through site-selective reaction of 1,4-dialkylpiperazines or via a sequential N-functionalization of 1-methylpiperazine obviating laborious protection/deprotection steps.
DOI:
10.1055/s-0042-1751555
作为产物:
描述:
、 o-Nitro-benzamidoxim 、 氯甲酸乙酯 以
吡啶 为溶剂,
反应 1.0h,
以to form a 3-(2-nitrophenyl)-1,2,4-oxadiazolin-5-one of Formula (LIV)的产率得到3-(2-Nitrophenyl)-1,2,4-oxadiazolin-5-one