The preparation, spectral properties, structures, and base-induced cleavage reactions of some α-halo-β-ketosulfones

Abstract

The halogenation of β-ketosulfones such as α-methylsulfonylacetophenone (1) and benzenesulfonylacetone (10) can be effected with sulfuryl chloride or pyridinium bromide perbromide. Regiochemical control can be achieved by control of stoichiometry and/or the reaction conditions. Detailed 1H and 13C nmr, and mass spectra are recorded for a series of halogenated β-ketosulfones, together with structures by X-ray crystallography for 1, 2-chloro-2-methylsulfonyl-1-phenylethanone (2), chloromethyl methyl sulfone (4), and α-chloroacetophenone (21). Results from these studies are used to suggest a reason for the difficulty associated with substitution reactions of α-halosulfones.

2-Chloro-1,2-diphenylethanone (desyl chloride)

“…2). However, possibly due to steric hindrances from the bulky phenyl group next to the Cl substituent, the dihedral value is somewhat distorted in comparison to the molecular structure of 2-chloroacetophenone (Grossert et al (1984)), where the respective angle was found at 2.4 °.…”

“…For the crystal structure of 2-phenylacetophenone, see: Rieker et al (1993). For the crystal structure of 2-chloroacetophenone, see: Grossert et al (1984). Structures containing similar angles were retrieved from the Cambridge Structural Database (Allen, 2002).…”

Modelling One-Pot Method for Synthesis of 2,3-Dihydro-1<i>H</i>-pyrrolo[2,1-<i>c</i>][1,4]benzothiazine 5,5-Dioxides and Their Homologues

“…Elution started with water and ended with acetonitrile/water (95:5, v/v) and used a linear gradient at a flow rate of 0.15 mL/min and an analysis cycle time of 25 min. 1 [30][31][32], Oand S-methyl 2a-f [33,34] have been obtained as commercial substances similarly to the previously reported methods.…”

Halogenation of β-keto-sulfones using KX/H2O2in aqueous medium: Synthesis of α-halo β-keto-sulfones and α-halomethyl sulfones

“…In addition, β-keto-sulfones are useful for the synthesis of optically active β-hydroxy-sulfones [18][19][20][21] and α-halomethyl sulfones and α,α-dihalomethyl sulfones [22]. The α-halomethyl sulfones and α,α-dihalomethyl sulfones are very good α-carbanion stabilizing substituents [23] and they are precursors for the preparation of alkenes [24], aziridines [25], epoxides [26][27][28][29], β-hydroxy-sulfones and used as VNS adducts [30][31][32][33].…”