72725-81-6Relevant articles and documents
Selectivity in the Metalation of Polymethylpyrazines
Bassfield, Ronald L.,Houminer, Yoram
, p. 2130 - 2133 (2007/10/02)
The selectivity in the LDA-promoted lithiation of 2,3,5-trimethylpyrazine was studied by using the perdeuterated substrate 1-d9.Quenching of the lithium salts of the latter with H2O gave a 1-d8 isomer mixture which was analyzed by NMR.The order of reactivity of the three CH3 groups in 1-d9 was found to be 3 > 2 > 5.The metalation studies were extended also to isomeric dimethylpyrazines.It was established that the two ortho CH3 groups in 2,3-dimethylpyrazine are more easily metalated than either of the CH3 groups in the other isomeric dimethylpyrazines.
