Terminal Benzoylation of Certain β-Keto Sulfones to Form Diketo Sulfones by Means of Sodium Hydride. Dibenzoylation of Dimethyl Sulfone¹

The Three-Component Synthesis of 4-Sulfonyl-1,2,3-triazoles via a Sequential Aerobic Copper-Catalyzed Sulfonylation and Dimroth Cyclization

“…The most prominent alternative to the AAC synthesis of 4-sulfonyl triazoles is the Dimroth azide–enolate cycloaddition of sulfonyl ketones [ 3 , 21 , 22 , 23 , 24 ]. While previously reported room temperature Dimroth cyclizations furnished 4-sulfonyl triazoles in good to high yields [ 3 , 22 , 23 ], the requirement of prior synthesis and isolation of the sulfonyl ketones reduces their sustainability and attractiveness [ 3 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. Additionally, there are two alternative pathways, based on the Wolff triazole synthesis [ 36 , 37 ] and azide–alkene cycloaddition [ 38 , 39 , 40 ] that are both less attractive due to the use of unstable α-diazo-sulfonyl ketones, and the somewhat lower yields or availability of the starting materials.…”

Preparation of 5‐sulfonylpyrimidines from β‐keto, β‐cyano‐, and β‐ethoxycarbonyl‐β‐sulfonylenamines

“…Elemental analyses were performed on a Shimadzu U M 3 B microanalyzer. The starting material la[19], c[ZO], d[21], and e[22] were prepared by the literature methods.The compound l b was prepared according to the same procedure a5 la, mp 80 M. Takahashi, T. Mamiya and M. Wakao Vol. 23 Anal.…”

Synthesis of halo compounds for studies of potential benzyne cyclizations

“…These 1,3,5-triketones can be readily converted to the substituted 4H-pyran-4-one (7) by dissolving the ketone in concentrated sulfuric acid at 0°; this was readily shown by the conversion of halotriketone 3a to pyrone 4 in 70% yield. Chlorosulfone, 5, was prepared in 61% yield by the monobenzoylation of dimethyl sulfone with methyl o-chlorobenzoate by means of sodium hydride in monoglyme (6). Chloro-3-diketone alcohol, 6, was prepared in 43% yield by the condensation of dipotassioacetylacetone with o-chlorobenzophenone in liquid ammonia (6).…”

“…Chlorosulfone, 5, was prepared in 61% yield by the monobenzoylation of dimethyl sulfone with methyl o-chlorobenzoate by means of sodium hydride in monoglyme (6). Chloro-3-diketone alcohol, 6, was prepared in 43% yield by the condensation of dipotassioacetylacetone with o-chlorobenzophenone in liquid ammonia (6). Each compound was characterized by analysis (except lb) and absorption spectra.…”

“…The synthesis of spirocydic orthocarbonates by the alcoholysis of methyl or ethyl orthocarbonate was not possible because all attempts to prepare methyl and ethyl orthocarbonates (4, 6) by the reaction of chloropicrin and alkoxides and with several variants proved futile and resulted in a violent explosion when an attempt was made to distill the product. The Ponzio (5) synthesis using carbon tetrabromide was not attempted since only ''a very small quantity" was reported to form.…”