Condensation of acetylacetone with formaldehyde and thiols

Reaction of 3-(Alkylsulfanylmethyl)pentane-2,4-diones and 4-(Alkylsulfanyl)-3-(alkylsulfanylmethyl)butan-2-ones with Phenylhydrazine in the Presence of Zinc Chloride

“…Phenylhydrazine hydrochloride of chemicall pure grade (CAS 59-88-1) was purchased from Merck. Initial com pounds 1a-1c, 4a, and 4b were synthesized as described in [21,43].…”

“…While continuing studies of methods of synthesis of 4-[alkylsulfanyl(sulfonyl)methyl]-1H-pyrazoles from available dicarbonyl compounds [21][22][23][24], we have found that 3-[(alkylsulfanyl)methyl]pentane-2,4-diones 1a-1c reacted with an equimolar amount of phenyl-hydrazine in boiling methanol, as well as in ethanol or acetonitrile [19], to give up to 89% of 4-[(alkylsul fanyl)methyl]-1-phenyl-1H-pyrazoles 2a-2c (Scheme 1, Table 1). When the condensation of pentane-2,4-diones 1a-1c with phenylhydrazine was carried out in boiling methanol in the presence of 0.3-1 equiv of ZnCl 2 , apart from expected 1H-pyrazoles 2a-2c, we isolated 1-(3-methyl-1-phenyl-1H-pyrazol-4-yl)ethanone (3) in up to 56% yield.…”

“…The reactions described in this communication have no advantages over the previously developed methods of synthesis of 1H-pyrazoles 3 [28] and 5 [33,41], except for the availability of initial compounds [21][22][23][24]. Nevertheless, the possibility of these transforma tions should be taken into account while using α-(alkylsulfanylmethyl)-substituted ketones and diketones in the presence of Lewis acids.…”

Synthesis of Organochalcogen Compounds using Non-Conventional Reaction Media

“…Baeva and co‐workers reported a three‐component reaction of acetylacetone 193 , formaldehyde 24 b and alkylthiols 3 in water to the synthesis of 3‐[(alkylsulfanyl)methyl]pentane‐2,4‐diones 194 (Scheme ). When the condensation of acetylacetone 193 with propane‐, butane‐ or hexane‐1‐thiol 3 and formaldehyde was performed at room temperature, a mixture of diketones 194 and enol tautomers 195 was obtained in very good yields after 3 h (81‐95 %).…”

1,3-Diketones. Synthesis and properties

“…Multicomponent condensation of acetylacetone with formamide and thiols RSH (or NaSMe) in an alkaline sulfide solution (from Orenburg gas processing plant) was reported in [63] (Scheme 55). Acetylacetone and dibenzoylmethane reacted with acetophenone in DMSO in the presence of CuO and I 2 to give triketones 113 through phenacyl iodide and phenylglyoxal as intermediates [19] (Scheme 56).…”