One-Step Conversion of Acetophenones to α-Haloacetophenone Dimethyl Acetals Using DCDMH/DBDMH and Molecular Sieve in Methanol
摘要:
Using DCDMH/DBDMH as N-halo reagent, piperidine as catalyst, and 4-A molecular sieve as water-removing agent, alpha-haloacetophenone dimethyl acetals were directly obtained from the solvent of methanol. As to the substrates with electron-withdrawing groups, the conversions were 80-100%.
Mild and Efficient α-Chlorination of Carbonyl Compounds Using Ammonium Chloride and Oxone (2KHSO<sub>5</sub>·KHSO<sub>4</sub>·K<sub>2</sub>SO<sub>4</sub>)
A simple protocol for the α-monochlorination of ketones and 1,3-dicarbonyl compounds utilizing NH4Cl as a source of chlorine and Oxone as an oxidant in methanol without catalyst is presented. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent.