Thiophenesulfonyl chlorides

Finally, certain 3-substituted compounds can be prepared by utilizing the - meta) directing powet (cf. Section IV,B) of some groups in the 2-position which afterward can be removed. 3-Nitrothiophene is prepared by nitration of 2-thiophenesulfonyl chloride and by removal of the sulfonic acid group of the 4-nitro-2-sulfonyl chloride formed with superheated steam. Another approach to 3-nitrothio-phene is to nitrate 2-cyanothiophene, separate the 4-nitro-2-cyano-thiophene from the 5-isomer, hydrolyze, and decarboxylate. A final method of preparation of 3-nitrothiophene is by simultaneous de-bromination and decarboxylation of 5-bromo-4-nitro-2-thiophene-carboxylic acid obtained through the nitration of methyl 5-bromo-2-thiophenecarboxylate. 

These percentages follow the order of the -values of the substituents. On the other hand, Raynaud and Delaby obtained a mixture of 80% 4-nitro- and 20% 5-nitro-2-cyanothiophene, upon nitration of 2-cyanothiophene, which were separated by fractional crystallization. " In the nitration of 2-nitrothiophene, 85% 2,4-dinitrothiophene and 15% 2,5-dinitrothiophene is obtained. - The erroneous statement, in Hartough s monograph, that 2,5-dinitrothiophene is the main product, should be noted. Nitration of 2-thiophenesulfonyl chloride gives about 75% of the 4-isomer and 25% of the 5-isomer/ whereas in the sulfonation of 2-nitrothiophene apparently only the 4-isomer has been isolated. ... 

Such eliminations do not occur with chloro compounds. 2,5-Dichlorothiophene undergoes AlCU-catalyzed sulfonylation with ben-zenesulfonyl chloride. Attempts to extend this reaction to thiophene, 2,5-dimethylthiophene, and 2-chloro-5-iodothiophene resulted in the formation of intractable tars even with other catalysts. Sul-fones of this type are often prepared in much better yields by using thiophenesulfonyl chlorides and benzenes in the Friedel-Crafts reaction. ... 

Extensive studies have been carried out on the reaction of arenesulfonyl chlorides with aniline in methanol at 25 °C. These include various substituted thiophenesulfonyl chlorides. The kinetic data show that the rate-determining step in the reaction is addition of the nucleophile, rather than synchronous attack of amine and displacement of chloride (Scheme 162) (76AHC(20)1>. 

Nitrothiophene is best prepared by hydrolysis of 4-nitro-2-thiophenesulfonyl chloride with superheated steam (equation 42). Nitration of 2-thiophenesulfonyl chloride gives a... 

Thiophene sulfoxides and thiophene sulfones can be prepared by direct oxidation of the corresponding sulfides (Section 3.15.9.5.1) with hydrogen peroxide. 2-Thiophene sulfones are also prepared by reaction of arylsulfonyl chlorides with thiophene under mild Friedel-Crafts conditions, or by condensation of 2-thiophenesulfonyl chlorides with aromatic compounds (Section 3.14.2.4). 

Reaction of 274 with 2-thiophenesulfonyl chloride gave 275 (86EUP 150974) and with p-toluenesulfonyl isocyanate gave the sulfonyl urea 276... 

Carboxylic acids, acyl chlorides, and sulfonyl chlorides used for deri-vatization of 4-aminophenylalanine and >-4-am i n op h e ny I a I a n i n e are as follows 5-hydantoinacetic acid, / ran, v - 4 - co t i n i n ec a r b o xy I i c acid, isonicotinic acid, 3-pyridinepropionic acid, 4-hydroxyphenylacetic acid, 2-butynoic acid, 2-pyrazinecarboxylic acid, cyclopropanecarboxylic acid, 3-hydroxy-2-qui-noxaline carboxylic acid, 5-bromovaleric acid, propargyl chloroformate, 3,4-dimethoxybenzoyl chloride, 2-thiophenesulfonyl chloride, 3-thiophene-carboxylic acid, 2-thiophenecarboxylic acid, 2-methylbutyric acid, 2-thio-pheneacetyl chloride, benzoic acid, furylacrylic acid, 4-nitrophenyl acetic acid, 2,5-dimethoxyphenylacetic acid, p-toluenesulfonyl chloride, 4-(di-methylamino)phenylacetic acid, 3-indolepropionic acid, phenoxyacetic acid, 3-(dimethylamino)benzoic acid, cyclohexanecarboxylic acid, naphtha-lenesulfonyl chloride, 4-bromophenylacetic acid, 4-bromobenzoic acid, 2-phenoxybutyric acid, 3,4-dichlorophenylacetic acid, (l-naphthoxy)acetic acid. 

While cooling with ice, AM-butylamine (0.82 mol) was added dropwise to a solution of 2-thiophenesulfonyl chloride (0.27 mol) in 500 ml CH2C12 and the solution stirred 1 hour at ambient temperature. The mixture was then diluted with 500 ml 1M HC1 and the organic phase isolated. The solution was washed with water, dried over Na2S04, concentrated, and 58.2 g product isolated as a pale yellow oil. 

Research is going on to improve the DELFIA system , because of drawbacks such as the time-consuming conversion of the non-fluorescent RE label into a luminescent complex, or the system vulnerability to contamination by RE due to the excess of the reagents ntfa and topo. An alternative is the use of a -diketone that can be covalently bonded to proteins such as 5-(4,4,4-trifluoro-l,3-dioxobutyl)-2-thiophenesulfonyl chloride (ctta) . Since the stability of the RE + complexes formed by this ligand is quite low, a large excess of RE + has to be used to shift the equilibrium to the rare-earth complex. More stable europium complexes can be obtained by the use of tetradentate fi-diketonates, such as 7a-7d, anchored on a functionalized o-terphenyl skeleton, or 8a-8c, anchored on a biperfluorobutadiene skeleton . ... 

The reactions of furansulfonyl chlorides with anilines (entry 11)123 in MeOH yield a linear Bronsted plot with fix =0.51, which indicates an Sw2 mechanism rather than a stepwise process. This value is quite similar to those found for the reactions of anilines with benzenesulfonyl chloride (0.63)117, with 2-thiophenesulfonyl chloride (0.53)124 and with 3-thiophenesulfonyl chloride (0.54)125. Thus their anilinolysis mechanism is also expected to be S/y2. The reaction rate therefore depends not only on the nucleophile basicity but also on the substrate reactivity. Comparison of the reaction rates leads to the following reactivity order for the Ar moiety benzene > 3-thiophene > 3-furan > 2-furan > 2-thiophene. This reactivity sequence follows the order of the resonance interaction between the... 

Thiophenesulfinic acid 541,542 2-Thiophenesulfonyl chloride is dissolved in several parts of water and cooled whilst being treated gradually with zinc dust. When the odor of the sulfonyl chloride has disappeared the pasty mixture is filtered and the solid is washed free from zinc chloride by water. The residue consisting of zinc thiophenesulfinite and the excess of zinc dust is treated with sodium carbonate solution which converts the zinc salt into the sodium salt which is readily soluble in water. The solution is filtered, greatly concentrated on a water-bath, and acidified. The sulfinic acid is taken up in ether. On removal of the ether it is obtained as an oil that solidifies to needles, m.p. 67°, when kept in a vacuum over sulfuric acid. 

Several thiophenesulfonyl chlorides have been prepared by using the DMF-SOjClj complex for chlorosulfonation <85BCJ1063>. This reaction failed with 2-acetylthiophene, which gave only unidentified materials. In the case of 2-methoxythiophene, only formylation at position 5 resulted. Sulfonation of 2-acetylthiophene at position 5 has been achieved in 93% yield by first converting... 

Reactions of 2-Thiophenesulfonyl Chloride with Anilines. Arcoria and coworkers (126) have studied solvent effects on the kinetics of the reactions of 2-thiophenesulfonyl chloride with a series of ring-substituted aniline derivatives. Using the data in the eight of their solvents which are aliphatic and whose solvatochromic parameters are known (18,50,102,103,104,105,111,112), we have found correlations with tt and a to be excellent. 

Thiophenecarboxaldehyde 3-Thiophenecarboxaldehyde 2-Thiophenecarboxylicacid 3-Thiophenecarboxylicacid 2,5-Thiophenedicarboxylicacid 2-Thiophenemethanol 2-Thiophenesulfonyl chloride... 

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