666714-63-2Relevant articles and documents
Hexafluoroisopropanol as solvent and promotor in the Paal-Knorr synthesis of N-substituted diaryl pyrroles
Schirmacher, Robert H.E.,R?sch, Daniel,Thomas, Franziska
, (2021/02/20)
An additive-free synthesis of challenging N-substituted aryl pyrroles from the often poorly soluble corresponding 1,4-diketones by means of the Paal-Knorr pyrrole synthesis is reported, which makes use of the unique properties of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as a solvent and reaction promotor. Our procedure offers simple execution and purification as well as easy scale-up and can be applied in the Paal-Knorr synthesis of a large number of structurally diverse pyrroles including the synthetically challenging tetra- and penta-substituted pyrroles in moderate to excellent yields. HFIP can also be used as solvent in the Paal-Knorr synthesis of furans and thiophenes; however, the solvent effect is more pronounced in synthesis of pyrroles.
An efficient method for the N-debenzylation of aromatic heterocycles
Rao, T. Srinivasa,Pandey, Pramod S.
, p. 3121 - 3127 (2007/10/03)
The N-debenzylation of aromatic heterocycles such as substituted pyrroles and indoles, having functional groups like ester, amide, halo, and nitrile, by using sodium in liquid ammonia in the presence of t-BuOH at -78°C cleanly affords N-debenzylated aromatic heterocycles in good yields.