Nuclear magnetic resonance investigations of carbonium ion intermediates. Part I. Kinetics and mechanism of formation of the Vilsmeier–Haack reagent

Abstract

The mechanism of formation and the structure of the Vilsmeier reagent (dimethylformamide and POCI,, SOCI,, or COCI,) has been studied by use of kinetic and structural data obtained from l H and 31P n.m.r. spectroscopy. The rate constants and activation energies are discussed in terms of structural changes and solvent effects.

Ultrasonically Assisted Synthesis of Aromatic Sulfonic Acids under Vilsmeier Haack Conditions in Acetonitrile Medium

“…The Vilsmeier Haack (VH) reaction [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] is widely used for formylation. It can be applied to introduce an acetyl group on activated aromatic or hetero aromatic compounds, many other conversions can be achieved with this technology.…”

Synthesis of Iminium Salts, Orthoesters and Related Compounds

“…4 ,5,7,78-81 The adduct formation either from thioamides and POCl3 or amides and PSCl3 has been studied. 82 The adduct of N,N-dimethylthioformamide with POCb is said to be more reactive than the oxygen analog adduct. 4 ,5,7 It has been demonstrated that DMF undergoes selfcondensation with PSCl3 to give N,N-dimethylglyoxylicthioamide For preparative purposes it should be kept in mind that the use of these adducts, e.g.…”

Electrophilic Substitution of the Pyrrole Ring

“…(193) The azafulvenium intermediate (F7) can be isolated as its perchlorate salt by the addition of sodium perchlorate to the reaction mixture. (193) The azafulvenium intermediate (F7) can be isolated as its perchlorate salt by the addition of sodium perchlorate to the reaction mixture.…”