Novel routes to 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines.
Condensation reactions of benzotriazole and 2-(pyrrol-1-yl)-1-ethylamine (1) with formaldehyde and glutaric dialdehyde, respectively, afforded intermediates 2 and 6. Subsequent nucleophilic substitutions of the benzotriazole group in 2 and 6 with Grignard reagents, sodium cyanide, and sodium borohydride gave 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines 3a-e, 4, 5 and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines 7a-c, 8, 9, respectively, in good yields.
Katritzky
Alan R
AR
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA. katritzky@chem.ufl.edu
Jain
Ritu
R
Xu
Yong-Jiang
YJ
Steel
Peter J
PJ
D015394:Molecular Structure; D011719:Pyrazines / Q000138:chemical synthesis* / Q000737:chemistry; D011759:Pyrrolidines / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism; D014230:Triazoles / Q000737:chemistry
D011719:Pyrazines; D011759:Pyrrolidines; D014230:Triazoles; C012771:benzotriazole