The synthesis of tetrafluoro-sulphobenzoic acids and their derivatives

The tetrafluorosulphobenzoic acids 1,2-HO₂C.C₆F₄.SO₃H (I) and 1,4-HO₂C.C₆F₄.SO₃H (II) have been synthesised [1] by oxidation of respectively 4,5,6,7-tetrafluorobenzo [b] thiophen- 2-carboxylic acid (III) [2] and 4-mercaptotetrafluorobenzoic acid (IV) [3].By-products were obtained when (III) was oxidised with either trifluoroperacetic acid or potassium permanganate.A number of reactions of these intermediates have been investigated and the products characterized, eg reaction of (I) with SoCl₂ gave tetrafluoro-1,2-sulphobenzoic acid cyclic anhyride (V). Although no significant change was observed when (II) was similarly treated reaction of (II) with DMF/SOCl₂ gave 1,4-Cl.C₆F₄.COCl. The diacid fluorides 1,2-FOC.C₆F₄.SO₂F (VI) and 1,4-FOC.C₆F₄.SO₂F (VII) were obtained when (I) and (II) respectively were reacted with sulphur tetrafluoride. The use of excess SF₄ gave 1,2- or 1,4- [F₃C.C₆F₄.SO₂F].     

Anionarylation of acrylic and methacrylic acids derivatives with p- and m-phenylenebisdiazonium tetrafluoroborates

Chloro-, bromo- and thiocyanatoarylation of amides and nitriles of acrylic and methacrylic acids with bisdiazonium salts based on m- and p-phenylenediamines have been studied. 3,3′-[1,4(3)-phenylene]bis[2-halopropanamides(nitriles)] and 2-thiocyanato-(2-methyl)-3-[4(3)-thiocyanatophenyl]propinamides have been obtained as bishaloarylation and monothiocyanatoarylation products, respectively.     

The mechanism of the diene synthesis with 5-alkoxyoxazoles

The reaction of 5-ethoxyoxazole with -acetylacrylic acid and its ethyl ester is examined, and the most probable mechanism for the heterodiene synthesis with oxazoles is suggested on the basis of the experimental results and on the calculation of the -electron densities for these molecules.     

Photoinduced diastereoselective addition of perfluoroalkyl iodides to acrylic acid derivatives for the synthesis of fluorinated amino acids

Photoinduced diastereoselective addition of perfluoroalkyl iodides in the presence of an aqueous solution of Na2S2O3 was an excellent method for iodoperfluoroalkylation of acrylic acid derivatives bearing a chiral auxiliary, with moderate to good stereoselectivities and with no detectable side products. The iodoperfluoroalkylation of N-acyloylcamphorsultam provided a convenient route for preparing chiral fluorine-containing amino acids.     

The interaction of antitumor active vanadocene dichloride with sulfur-containing amino acids

Vanadocene dichloride (1) reacts with sulfur-containing amino acids, cysteine and methionine, giving new complexes with five- or six-membered chelate ring, but the structure of isolated compounds is affected by the pH value of the reaction mixture. Methionine reacts with aqueous 1 in the pH range of 3-8 affording chelate structure [Cp₂V(N,O-met)]Cl (4). Similar reaction with cysteine gives two different products depending on pH. In the acidic solution, the complex [Cp₂V(O,S-cys)]Cl (2) is present, whereas in neutral media the compound [Cp₂V(N,S-cys)] (3) could be identified. On inspection of spectroscopic measurements, particularly EPR and vibrational spectroscopy, it is evident that sulfur atom of amino acid is bonded directly to the vanadium atom of [Cp₂V]²⁺ moiety. For the purpose of comparison the complexes [Cp₂V(O,S-mpa)] (5) and [Cp₂V(N,S-csam)]⁺ (6a) with related chelating ligands, 3-mercaptopropionic acid (mpa) and cysteamine (csam), respectively, were prepared and spectroscopically characterized. The structure of the complex [Cp₂V(N,S-csam)]BPh₄ (6b) was also determined by X-ray diffraction analysis.     

Synthesis of sulfur-containing dehydrodesthiobiotin derivatives

Conclusions The reduction of the ethyl esters of- and'-oxodehydrodesthiobiotin with sodium borohydride, and subsequent treatment of the intermediate hydroxy esters with thioacetic acid, gave the ethyl esters of- and'- (aceitylmercapto)dehydrodesthiobiotin.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2626–2627, November, 1973.We express our gratitude to V. V. Filippov for running the biological tests on (V), (VI) and (XI).     

The Mannich-type interaction of sulfur-containing CH acids with formaldehyde and primary amines

One-pot reactions of dimethyl sulfonyldiacetate and N-methyl-2r,6c-di(methoxycarbonyl)-3t,5t-diphenyltetrahydro-1,4-thiazine 1,1-dioxide with formaldehyde and primary amines lead to derivatives of 9-thia-3,7-diazabicyclo[3.3.1]nonane 9,9-dioxide resulted from decarboxylation of the ester groups at the positions 1 and 5. The effects of the reaction conditions and structure of the starting reagents on the yields of 9-thia-3,7-diazabicyclo[3.3.1]nonane 9,9-dioxides were studied.     

Chloromethyl derivatives of 3-furyl-3-(diethoxyphosphoryl)acrylic acids

Methoxymetyl derivatives of furoylphosphonates react with ethoxymethylenetriphenylphosphoranes to give phosphorylated (methoxymethylfuryl)acrylates. The reaction proceeds stereoselectively: phosphoryl and ester groups at the double bond are always trans-located. Treatment with dichloromethylmethyl ether and catalytic amount of zinc chloride converts the methoxymethyl group in the synthesized compounds into chloromethyl one. The ester group and the double bond are inert under these conditions.     

Palladium/phosphite-catalyzed 1,4-addition of arylboronic acids to acrylic acid derivatives

1,4-Addition of arylboronic acids to acrylic acid derivatives proceeds efficiently in the presence of a palladium catalyst system of Pd(OAc)2/(PhO)3P to produce the corresponding 3-arylpropionic acid derivatives. The use of the phosphite ligand is the key to conducting the addition smoothly with suppressing the competing Mizoroki-Heck-type oxidative coupling.     

New synthesis of 3-(4-thiazolyl)acrylic acids

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1577–1578, November, 1993.