Novel Synthesis of 1,2,3,4-Tetrahydropyrazino[1,2-a]indoles.
Condensation of 2-(3-methyl-1H-indol-1-yl)ethylamine (7) with benzotriazole and formaldehyde gave 2-(1H-1,2,3-benzotriazol-1-ylmethyl)-10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indole (8) in 96% yield. Nucleophilic substitutions of the benzotriazolyl group in 8 with NaBH(4), NaCN, triethyl phosphite, allylsilanes, silyl enol ether and Grignard reagents afforded novel 10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indoles 9a-i in 78-95% yields.
Katritzky
Alan R
AR
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA. katritzky@chem.ufl.edu
Verma
Akhilesh Kumar
AK
He
Hai-Ying
HY
Chandra
Ramesh
R