L. V. Saloutina

Synthesis of polyfluoroalkylated 1,4-diazinols and 1,4-oxazinols using polyfluoro-2,3-epoxyalkanes32 + 13

Abstract It has been found that the reactions of polyfluoro-2,3-epoxyalkanes with ethylenediamine and 2-aminoethanol yield 2,3-di(polyfluoroalkyl) 1,5,6-trihydro-1,4-diazin-2-ols and 2,3-di(polyfluoroalkyl) -5,6-dihydro-1,4-oxazin-2-ols, respectively. In the case of unsymmetrical oxiranes mixtures of regioisomeric heterocyclic compounds have been obtained. These reactions were found to give some byproducts—N,N′-bis (polyfluoroacyl)ethylenediamines and N-polyfluoroacyl-2-aminoethanols.

From oxides of internal perfluoroolefins to fluorocontaining camphor thiazolinylhydrazones

Abstract The reaction of oxides of internal trans - and cis -perfluoroolefins with ( 1S , 4S )- or racemic camphor thiosemicarbazone leads to the formation of trans - and cis -isomers of ( 1S , 4S )- or racemic camphor 5′-fluoro-4′-hydroxy-4′,5′-di(perfluoroalkyl)-1′,3′-thiazolinyl-2′-hydrazones, respectively. Unsymmetrical dodecafluoro-2,3-epoxyhexane yields a mixture of regioisomeric hydrazones. The molecular structure of the trans -isomer of ( 1S , 4S )-camphor 5′-fluoro-4′-hydroxy-4′,5′-bis(trifluoromethyl)-1′,3′-thiazolinyl-2′-hydrazone has been established by X-ray crystallography. The quite rare example of cocrystallization of two diastereomers of the latter in homochiral crystal (sp. group P2 1 ) has been revealed.

Polyfluoroalkylated 1,3-thiazolines: synthesis from polyfluoro-2,3-epoxyalkanes

Abstract The interaction of polyfluoro-2,3-epoxyalkanes with thiourea and thiosemicarbazide results in 2-amino-5-fluoro-4-hydroxy-4,5-di(polyfluoroalkyl)-1,3-thiazolines and 5-fluoro-2-hydrazino-4-hydroxy-4,5-di(polyfluoroalkyl)-1,3-thiazolines, respectively. Asymmetric oxiranes yield mixtures of regioisomers, and the ring opening has been found to occur mainly near the bulkier fluoroalkyl group. The reaction with thiourea proceeds stereospecifically in dimethyl sulfoxide. The molecular structure of E -isomers of 2-amino-5-fluoro-4-hydroxy-4,5-bis(trifluoromethyl)-1,3-thiazoline and 2-amino-5-fluoro-5-heptafluoropropyl-4-hydroxy-4-trifluoromethyl-1,3-thiazoline has been established by X-ray crystallography.

Reactions of epoxides derived from internal perfluoroolefins with o-phenylenediamine and 2-aminophenol

The reactions of epoxy derivatives of internal perfluoroolefins with o-phenylenediamine and 2-aminophenol in dioxane gave 23–67% of the corresponding 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-2H-1,4-benzoxazin-2-ols, respectively. When N,N-dimethylacetamide was used as a solvent, the main reaction pathway was anionic isomerization of epoxides into ketones which were then converted into 2-perfluoroalkylbenzimidazoles (in the reactions with o-phenylenediamine) or 2-hydroxy-N-perfluoroalkanoylanilines (in the reactions with 2-aminophenol). The reaction of 3,4-epoxydodecafluorohexane with 2-aminophenol in N,N-dimethylacetamide was accompanied by unusual cyclization to afford 2-pentafluoropropanoyl-2-pentafluoroethyl-1,3-benzoxazolidine.

Reactions of internal perfluoroolefin oxides with urea

Internal perfluoroolefin oxides reacted with urea to give, depending on the solvent nature, two types of new fluorine-substituted nitrogen-containing heterocycles. 1,5-Bis(perfluoroalkyl)tetraazabicyclo[3.3.0]octane-3,7-diones were formed in dimethyl sulfoxide, N,N-dimethylacetamide, and acetonitrile, while the reaction in dioxane resulted in the formation of unexpected products, 2-amino-5-fluoro-4,5-bis(perfluoroalkyl)-4,5-dihydrooxazol-4-ols, existing mainly as trans isomers. trans Orientation of perfluoroalkyl substituents in these compounds was determined by analysis of 19F-19F spin-spin coupling constants in the 19F NMR spectra. The molecular structure of trans-2-amino-5-fluoro-4,5-bis(trifluoromethyl)-4,5-dihydrooxazol-4-ol was studied by X-ray analysis.

2,3-Epoxyperfluoro-2-methylpentane in reactions with urea and thiourea

Abstract2,3-Epoxyperfluoro-2-methylpentane reacts with thiourea in protic (methanol, 2-propanol) and aprotic (dioxane) solvents, and also with urea in acetonitrile affording unexpected products: 1-(2,2,3,3,3-pentafluoropropionyl)-2-(2,2,2-trifluoro-1-trifluoro-methylethyl)isothiourea, and 1-(2,2,3,3,3-pentafluoropropionyl)-3-(2,2,2-trifluoro-1-trifluoro-methylethyl)urea respectively that result from the rearrangement of the intermediately formed ketone in the process of the intramolecular “haloform” cleavage. At the same time in dioxane the 2,3-epoxyperfluoro-2-methylpentane reacts with urea with the formation of a heterocyclic compound, 2-amino-4-pentafluoroethyl-5,5-bis(trifluoromethyl)-4,5-dihydrooxazol-4-ol. From 1-(2,2,3,3,3-pentafluoropropionyl)-2-(2,2,2-trifluoro-1-trifluoromethylethyl)isothiourea and Cu(OAc)2 a stable fluorine-containing chelate complex was obtained.

Novel route of the reaction of trifluoromethyl-containing N-methyl(4-ethoxyphenyl)imidazolidin-2-ones with urea

The reactions of perfluorobiacetyl with N-(4-ethoxyphenyl)- and N-methylurea afforded cis- and trans-isomers of 1-methyl-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one and 1-(4-ethoxyphenyl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one in a yield of ∼60—75%. N-Alkyl(aryl)bis(trifluoromethyl)imidazooxazoles were obtained as unexpected products in the reaction of 1-alkyl(aryl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones with urea in dimethylacetamide. The reaction is accompanied by the rearrangement of imidazolidin-2-ones to N-alkyl(aryl)-5,5-bis(trifluoromethyl)hydantoins with CF3 group migration from position 5 to position 4 of the starting heterocycle. A similar rearrangement is observed on boiling of the studied imidazolidin-2-ones in dimethylacetamide. The molecular structures of 3-(4-ethoxyphenyl)-5,5-bis(trifluoromethyl)imidazolidine-2,4-dione and 6-(4-ethoxyphenyl)-3a,6a-bis(trifluoromethyl)tetrahydroimidazo[4,5-d]oxazole-2,5-dione were studied by X-ray diffraction analysis.

Synthesis of fluorine-containing heterocycles based on polyfluorooxiranes and O,N,S-dinucleophiles

The methods of synthesis of fluorine-containing O, N, S-heterocyclic compounds, such as diazines, oxazines, thiazolines, oxazolines, quinoxalines, benzoxazines, benzothiazines, imidazolidines, and glycolurils, based on the reactions of perfluoro- and polyfluorooxiranes with bifunctional nucleophilic reagents, are presented in the review. Significant influence of the solvent nature on the composition and structure of the obtained compounds is demonstrated.

Reaction of 2,3-epoxyoctafluorobutane with 2-aminobenzenethiol

The reaction of 2,3-epoxyoctafluorobutane with 2-aminobenzenethiol in N,N-dimethylacetamide gave 3-(2-aminophenylsulfanyl)-1,1,1,3,4,4,4-heptafluorobutane-2,2-diol. In the reaction of the same compounds in dioxane, 2,3-bis(trifluoromethyl)-3,4-dihydro-2H-1,4-benzothiazin-2-ol was formed as a result of primary attack by the amino group in 2-aminobenzenethiol on the epoxy ring. The same product was obtained by treatment with 2-aminobenzenethiol of 2,3-bis(trifluoromethyl)-2H-1,4-benzoxazin-2-ol which was synthesized from 2,3-epoxyoctafluorobutane and 2-aminophenol.

Reaction of Internal Fluoroolefin Oxides with Camphor Thiosemicarbazone

Epoxy derivatives of internal fluoroolefins (both cis and trans isomers) react in a stereospecific manner with (1S)- or rac-camphor thiosemicarbazone in a polar aprotic medium to give the corresponding 5-fluoro-4-hydroxy-4,5-bis(polyfluoroalkyl)thiazol-2-ylhydrazones. From unsymmetrical 2,3-epoxydodecafluorohexane a mixture of regioisomeric hydrazones is formed. According to the 1H and 19F NMR data, the resulting trans-hydrazones in (CD3)2SO and CDCl3 exist as mixtures of diastereoisomers occurring in a dynamic equilibrium.