Sulfonyl Chloride Derivatives Research Articles

Synthesis, in silico ADMET prediction analysis, and pharmacological evaluation of sulfonamide derivatives tethered with pyrazole or pyridine as anti-diabetic and anti-Alzheimer's agents

Based on previous developments of our research programs in trying to find new compounds with multiple biological targets such as antioxidant, anti-diabetic, anti-Alzheimer's, and anti-arthritic agents. In the context, a novel series of sulfonamide derivatives based on the pyrazole or pyridine moieties 3a, b, 7–9, 11–13, 15a, b, and 16 were synthesized from amine compounds with sulfonyl chloride derivatives. The structures of sulfonamide derivatives were elucidated via spectroscopy (1H and 13C NMR). The sulfonamide derivatives were biologically assessed in vitro for their anti-diabetic (α-amylase and α-glucosidase inhibition) and anti-Alzheimer's (acetylcholinesterase inhibition) activities. The biological results revealed that compound 15a is a powerful enzyme inhibitor for α-amylase and α-glucosidase. Also, compound 15b demonstrated inhibitor activity against the acetylcholinesterase enzyme. The structure–activity relationship study of sulfonamide derivatives was accomplished. Furthermore, complementary in silico molecular properties, drug-likeness, ADMET prediction, and surface properties of the two more powerful derivatives 15a and 15b were fulfilled and computed. These studies recommend 15a and 15b as candidates with modifications in their structures before the in vivo assays.

Novel benzene sulfonamides with acetylcholinesterase and carbonic anhydrase inhibitory actions.

A series of benzene sulfonamides 15-26 were synthesized and determined for their in vitro and in silico inhibitory profiles towardacetylcholinesterase (AChE) and carbonic anhydrases (CAs). Commercially available 3,4-dimethoxytoluene was reacted with chlorosulfonic acid to furnish benzene sulfonyl chloride derivatives. The reaction of substituted benzene sulfonyl chloride with some amines also including (±)-α-amino acid methyl esters afforded a series of novel benzene sulfonamides. In this study, the enzyme inhibition abilities of these compounds were evaluated against AChE and CAs. They exhibited a highly potent inhibition ability on AChE and -CAs (Ki values are in the range of 28.11 ± 4.55 nM and 145.52 ± 28.68 nM for AChE, 39.20 ± 2.10 nM to 131.54 ± 12.82 nM for CA I, and 50.96 ± 9.83 nM and 147.94 ± 18.75 nM for CA II). The present newly synthesized novel benzene sulfonamides displayed efficient inhibitory profiles against AChE and CAs, and it is anticipated that they may emerge as lead molecules for some diseases including glaucoma, epilepsy, and Alzheimer's disease.

Molecular Modeling Study of Bis-sulfonamide Derivatives Synthesis Targeting Aromatase Enzyme as Anticancer

Most studies indicate the important role of estrogen in the mechanism of occurrence and development of breast cancer. The importance of our research is the synthesis of bis-sulfonamide compounds that inhibit the aromatase enzyme, which is the main enzyme in the biosynthesis of estrogen. Molecular modeling of studied compounds was carried out by Molegro Virtual Docker (MVD) targeting aromatase enzyme and binding energy calculated to select the most encouraging compound. The highest binding energy among the studied compounds was -118.52 kcal/mol (compound A5) comparing with the aromatase substrate androstenedione -132.51 kcal/mol and the aromatase inhibitor letrozole -136.52 kcal/mol. Several of these compounds were synthesized in a simple way with good yields by reacting sulfonyl chloride derivatives with amino derivatives in an alkaline aqueous solution, or in a pyridine solution. The physicochemical characteristics and identification of synthesized compounds were determined by various analytical methods such as Mass spectrometry, Infrared spectroscopy and Nuclear Magnetic Resonance.

Synthesis of non-ionic surfactants nano-vesicles for clarithromycin oral delivery

Abstract In order to improve the solubility and bioavailability of poorly water-soluble drugs, the synthesis of cost-effective nonionic surfactants has been the subject of greater scientific interest. The present study focuses on the synthesis of sulfonyl chloride derivatives as nonionic surfactants (surfactant 1 and surfactant 2) and their evaluation for the preparation of a clarithromycin-loaded niosomal drug delivery system. Surfactants 1 and 2 were characterised by EI-MS and 1H NMR spectroscopy. The shape and size of the drug-loaded niosomal vesicles from the synthesised surfactants were examined by atomic force microscopy (AFM) and revealed a round morphology with an average size of (230.8 ± 2.35) nm and (248.1 ± 2.54) nm for the vesicles of surfactant 1 and surfactant 2, respectively. The zeta potential of surfactant 1-based niosomal vesicles was (– 7.70 ± 1.00) mV and that of surfactant 2 was (−14.6 ± 1.08) mV. The lower zeta potential values for surfactant 1 and surfactant 2-based niosomal vesicles showed that these vesicles were neutral and relatively stable. The vesicles of surfactant 1 and 2 have a capacity to entrap the drug of about (62 ± 2.26) % and (69.67 ± 3.23) %, respectively. The vesicles of surfactant 1 released the largest amount of drug, i.e. (70.00 ± 2.45) % at pH 1.2. Biocompatibility in human blood and toxic effects on various cell lines were also studied for surfactants 1 and 2, and they were found to be biocompatible and non-cytotoxic.

Thiophenyl-chalcone derivatives: Synthesis, antioxidant activity, FMO energies and molecular parameters

In this study, a series of thiophenyl-chalcones derivatives was synthesized and their DPPH and ABTS activities were evaluated. All thiophenyl-chalcones exhibited high antioxidant activity. Among them, 4e ((E)-5-(3-(4-(chlorosulfonyl)-3-hydroxyphenyl)-3-oxoprop-1-en-1-yl)thiophene-2-sulfonyl chloride) have higher ABTS activity (IC50 = 13.12 μM) than quercetin (IC50 = 15.49 μM), well-known as antioxidant agent and used as a standard. The structure-activity relationship results revealed that most of synthesized sulfonyl chloride derivatives (4a-e) have higher antioxidant activity than the sulphonamide derivatives (5a-c) and also 4d and 4e including hydroxyl group, exhibited the strongest antioxidant activity as expected. Additionally, the frontier molecular orbitals (FMOs) energies and molecular parameters of the synthesized molecules were calculated to support experimental results. The quantum chemical calculation results indicated that the strongest antioxidant compounds, in this study, had the lowest LUMO energies and the highest electronegativity, electron affinity and electrophilicity index.

Recent Advances in the Chemistry and Biological Activity of Sulfonamide Derivatives

Abstract: This review describes different synthetic methods for the preparation of sulfonamides. Generally, sulfonamides are synthesized from sulfonyl chloride derivative and amino derivative. A series of sulfonamide derivatives 7a-c, 8a,b, 9, 10, 11a,b, and 12 were synthesized in alkaline media by reacting different amino compounds with a p-toluene sulfonyl chloride. Different amino derivatives 13, 15, 17, 19, and 21 reacted with p-tolyl sulphonyl chloride to afford sulfonylamides 14, 16, 18, 20, and 22. Different reactions of sulfonamide derivatives have been summarized. Generally, the sulfonamide function group does not participate in any reactions, but other functional groups in the compound are involved in various reactions. Sulfonamides exhibit different biological activities, e.g., antibacterial activity, anticancer activity, urease inhibitory activity, radical scavenging activity, carbonic anhydrase inhibitory activity, non-competitive lactoperoxidase inhibitory activity, antifungal activity, and anti-mycobacterial activity.

New chalcone-sulfonamide hybrids exhibiting anticancer and antituberculosis activity

New sulfonamides 5/6 derived from 4-methoxyacetophenone 1 were synthesized by N-sulfonation reaction of ammonia (3) and aminopyrimidinone (4) with its sulfonyl chloride derivative 2. Sulfonamides 5 and 6 were used as precursors of two new series of chalcones 8a-f and 9a-f, which were obtained through Claisen-Schmidt condensation with aromatic aldehydes 7a-f. Compounds 5/6, 8a-d, 8f, 9a-d, and 9f were screened by the US National Cancer Institute (NCI) at 10 μM against sixty different human cancer cell lines (one-dose trial). Chalcones 8b and 9b satisfied the pre-determined threshold inhibition criteria and were selected for screening at five different concentrations (100, 10, 1.0, 0.1, and 0.01 μM). Compound 8b exhibited remarkable GI50 values ranging from 0.57 to 12.4 μM, with cytotoxic effects being observed in almost all cases, especially against the cell lines K-562 of Leukemia and LOX IMVI of Melanoma with GI50 = 0.57 and 1.28 μM, respectively. Moreover, all compounds were screened against Mycobacterium tuberculosis H37Rv, chalcones 8a-c and 9a-c were the most active showing MIC values between 14 and 42 μM, and interestingly they were devoid of antibacterial activity against Mycobacterium smegmatis and Staphylococcus aureus. These antituberculosis hits showed however low selectivity, being equally inhibitory to M. tuberculosis and mammalian T3T cells. The chalcone-sulfonamide hybrids 8a-f and 9a-f resulted to be appealing cytotoxic agents with significant antituberculosis activity.

Synthesis of novel sulfonamides under mild conditions with effective inhibitory activity against the carbonic anhydrase isoforms I and II

Novel sulfonamide derivatives 6a–i, as new carbonic anhydrase inhibitors which candidate for glaucoma treatment, were synthesized from the reactions of 4-amino-N-(4-sulfamoylphenyl) benzamide 4 and sulfonyl chloride derivatives 5a–i with high yield (71–90%). The structures of these compounds were confirmed by using spectral analysis (FT-IR, 1H NMR, 13C NMR, LC/MS and HRMS). The inhibition effects of 6a–i on the hydratase and esterase activities of human carbonic anhydrase isoenzymes, hCA I and II, which were purified from human erythrocytes with Sepharose®4B-l-tyrosine-p-aminobenzene sulfonamide affinity chromatography, were studied as in vitro, and IC50 and Ki values were determined. The results show that newly synthesized compounds have quite powerful inhibitory properties.

The composition and photolithographic process of high- thermostability ultraviolet positive photoresist

Photoresist is a crucial and fundamental material for photolithographic technology, which plays a vital role in microelectronic technique. The rapid development of lithography drives the microelectronic technique moving forward. With high-level and multifunctional photoresist, it can make finer patterns and meet the demand under harsh working environment such as high temperature. To evaluate the performance of the photoresist, one of the most important indicators is line/space resolution, while the composition of the photoresist and photolithographic process have a very significant influence on the resolution performance. Different composition may result in different photosensitivity and solubility of the photoresist, which have a significant impact on the performance. Moreover, the photolithographic processes include exposure dose (exposure time), developing time, the concentration of developer and so on. They all have severely affected the lithography pattern quality and lithography performance. Thus, the related research in detail is very necessary and it is conducive to maximize the performance of the photoresist and guide lithography process to be carried out smoothly as well. In this work, a high thermal-stability ultraviolet (UV) positive photoresist was obtained from the formulation of a self-made amide-imide copolymer as matrix resin, a 2,1,5-diazonaphthoquinone sulfonyl chloride derivative as photosensitizer, and solvent. The optimal composition and photolithographic process parameters was studied by simple variable method. It was found that the optimal composition was with the 1:4:10 (mass ratio) proportion of photosensitizer, resin and solvent, and the optimal photolithographic process parameters were about 4500 r/min spin-coating, prebake 1 min at 110°C hot plate, 30 s exposure time, 25 s development time in 1.0% tetramethylamine hydroxide (TMAH) aqueous solution, and post bake 5 min at 120°C hot plate. The imaging contrast of this photoresist was about 3.35, which indicated that the positive part and negative part of the pattern had obvious boundary. In the condition of contact exposure the lithography process above, the optimal line/space resolution was about 1 μm. In addition, the photoresist had high thermal-stability. After hard baking 30 min at 270°C, the photoresist had no obvious collapse of the photolithography pattern. This is because the self-made amide-imide copolymer has high thermal-stability and it acts as matrix resin in the photoresist. With the high thermal-stability property, the photoresist can meet the requirements of some used under high temperature environment and lays a foundation for the lithography technology being applied and developed under complex circumstance.

Synthesis of potent lymphocyte function-associated antigen-1 inhibitors labeled with carbon-14 and deuterium, part 1

The lymphocyte function-associated antigen-1 (LFA-1) is an essential component in normal immune system function and is a target for drug discovery for its broad therapeutic potential in treating inflammatory diseases. Here, we report the synthesis of three potent antagonists of LFA-1 labeled with carbon-14 and deuterium to support drug metabolism and pharmacokinetics studies. Carbon-14 labeled (R)-1-acetyl-5-(4-bromobenzyl)-3-(3,5-dichlorophenyl)-5-methyl-imidazolidine-2,4-dione (1) was prepared in 27% radiochemical yield in two steps and with a specific activity of 2.1 GBq/mmol by using [14C]-phosgene. Carbon-14 labeled 5-bromopyrimidine was used to prepare (R)-5-(1-piperazinylsulfonyl)-1-(3,5-dichlorophenyl)-3-[4-(5-pyrimidinyl)benzyl]-3-methyl-1-H-imidazo[1,2a]imidazol-2-one (2) and (R)-1-[7-(3,5-dichlorophenyl)-5-methyl-6-oxo-5-(4-pyrimidin-5-yl-benzyl)-6,7-dihydro-5H-imidazo[1,2-a]imidazole-3-sulfonyl]piperidin-4-carboxylic acid amide (3) via a Suzuki reaction with the corresponding boronic acid esters in 42% and 67% radiochemical yield and specific activities of 1.85 GBq/mmol and 1.95 GBq/mmol, respectively. Deuterium labeled piperazine was reacted with the sulfonyl chloride derivative (7), followed by a Suzuki coupling to the pyrimidine boronic ester to give deuterium labeled (2) in 47% yield. Deuterium labeled isonipecotamide was reacted in a similar way with the sulfonyl chloride derivative (14) to furnish deuterium labeled (3) in one step and in 94% yield. Copyright © 2011 John Wiley & Sons, Ltd.

A Convenient Synthesis of N-Functionalized Perfluoroalkanesulfonamides

This article describes the synthesis of new N-functionalized perfluoroalkanesulfonamides (5) with two sulfonamides functionalities. Perfluoroalkanesulfonyl fluoride underwent a reaction with 2-chloroethylamine hydrochloride or 3-bromopropylamine hydrobromide to give N-(2-chloroethyl or 3-bromopropyl) perfluoroalkanesulfonamides (1). Reaction of (1) with potassium thiocyanate gave N-(2-thiocyanatoethyl or 3-thiocyanatopropyl) perfluoroalkanesulfonamides (3). The sulfonyl chloride derivatives (4) were prepared by reaction of 3 with sulfuryl chloride. In the last step, 4 reacted with ammonia to give the bis sulfonamides derivatives (5). The structures of all new compounds prepared were determined by 1H, 19F, and 13C NMR spectroscopies and by HR-MS.

Insufficient taurine in enteral nutrition for patients

Reports have indicated that low levels of plasma taurine are present in patients undergoing long-term parenteral nutrition. Very little is known about the appropriate taurine contents in enteral nutrition, and taurine-fortified enteral nutrition formula is not available. This study was conducted to investigate the taurine contents of enteral solutions from China and Korea and to estimate daily intake of taurine in patients undergoing long-term enteral nutrition. The contents of taurine were measured as 4-dimethylaminoazobenzene-4′-sulfonylchloride derivative using high-performance liquid chromatography equipped with an RF detector. Blenderized enteral solutions from 8 Korean hospitals contained 7.6 ± 6.2 mg/L of taurine, whereas solutions from 12 Chinese hospitals contained 12.9 ± 19.8 mg/L. The estimated daily taurine intakes were 15.2 ± 12.4 and 25.9 ± 39.5 mg/d in Korean and Chinese patients, respectively, receiving blenderized enteral solutions. Taurine was not detected from the 12 Korean commercial formulas, whereas 8 Chinese commercial formulas contained 0.6 ± 1.2 mg of taurine per liter. The estimated daily taurine intakes of Korean patients who consume commercial formulas were 0 mg/2000 kcal per day and those of Chinese patients were 1.3 ± 2.4 mg/2000 kcal per day. These observations indicate that the amounts of estimated daily taurine intakes of patients receiving enteral solution were extremely low, thus suggesting that enteral nutrition solutions of both countries should be fortified with taurine.

Remarkably Mild and Simple Preparations of Sulfinates, Sulfonyl Chlorides and Sulfonamides from Thioanisoles

New and highly yielding procedures to convert thioanisoles into versatile sulfonyl chloride derivatives were developed by strategically taking advantage of the Pummerer reaction.

Texas Res-X and rhodamine Red-X, new derivatives of sulforhodamine 101 and lissamine rhodamine B with improved labeling and fluorescence properties.

Texas Red sulfonyl chloride (TR-SC) and Lissamine rhodamine B sulfonyl chloride (LRB-SC) are popular dyes often used to prepare red fluorescent conjugates that are useful second labels in combination with fluorescein. Unfortunately, being sulfonyl chloride derivatives, both are unstable to moisture during storage and prone to hydrolysis in the conjugation reaction. Their instability causes the percentage of reactive dye to vary from lot to lot and requires use of low temperatures and a relatively high pH to optimize conjugation efficiency. Succinimidyl esters of the aminohexanoic acid sulfonamides of both dyes have been prepared, which are designated Texas Red-X succinimidyl ester (TR-X-SE) and Rhodamine Red-X succinimidyl ester, respectively. Their spectral properties are similar to those of their sulfonyl chloride analogs; moreover, incorporation of the succinimidyl ester at the end of the aliphatic chain spacer facilitates conjugation, decreases precipitation of proteins during conjugation and storage, and usually increases the fluorescence yield of the conjugate. Comparison of the rate of hydrolysis of TR-SC with that of TR-X-SE shows that, while the former was completely hydrolyzed within 5 min by exposure to water, TR-X-SE retains most of its reactivity for more than an hour. The reactivity of both new derivatives is high between pH 7.5 and 8.5, allowing conjugation of proteins that do not tolerate the high pH required for reaction with sulfonyl chlorides. In addition, Texas Red maleimides and haloacetamides containing spacer groups were prepared for labeling sulfhydryl groups. A Texas Red-X derivative of phalloidin has also been prepared, and its use for labeling F-actin has been characterized.

A comparative study on the human placenta from uterinal and ectopic pregnancies by sem

A COMPARATIVE STUDY ON THE HUMAN PLACENTA F R O M UTER|NAL AND ECTOPIC PREGNANCIES BY SEM R. Demir (1 ) , T. Erbengi(2), N.Demir(1) and M.Elibol(2), Depar tmen t s of Histol. and E m b r y o l . , F a c u l t y of Medic ine , (1 )Akden iz Un ive r s i t y ,An ta lya , a n d (2)Marmara University, Istanbul,TURKEY The aim of this s tudy was to examine the development of c h o r i o n i c villous t rees emerg ing f rom chorionic plate dur ing ear ly pe r iods of uterinal and tubal pregnancy using SEM technique. In order to s tudy the three-dimensional s t ructures ,ear ly human placenta samples between 4-10 weeks(pc) were obtained f rom legal curretage and hys te rec tomy cases,and fixed in glutaraldehyde and osmium tetroxide for SEM. It a p p e a r e d that, the chorionic villus trees which emerge f r o m the chorionic plate divide gradual ly into branches of which ramif icat ions as buds. These buds gradually grew and were t ransformed into shoots. The numbers of developing new villi appeared to increase gradual ly f rom 28 days to 12 weeks of gestation. From 4th week the massive t rophoblas t ic sprou ts were obse rved on the surface of main chorionic villi which t r ans fo rm into p r i m a r y , s e c o n d a r y and ter t ia ry villus trees. When the placental villi fo rmat ion in ectopic pregnancy was c o m p a r e d with t he uter inal p regnancy ,ac tua l ly no sound deve lopment was remarkab le .The configurations of placental villi were seemed to be disparate,as if a racket or in a compressed position so that the three dimensional aspect had been wizened.The ramif ica t ion and new villi format ion seen as in the normal placenta were not only decreased but also infrequent. Some placental villi samples displayed a gradually thinning terminal region. According to our results, we comment that in ectopic p r egnancy the placental villi format ion and development could have been delayed. A.15 INHIBITION OF HUMAN PLACENTAL STERYLSULFATASE BY SYNTHETIC ANALOGUES OF ESTRONE SULFATE. L. Dibbelt, H. Nagel, Inst. Biochem. Endokrinol., Med. Univ., LQbeck, FRG; P.-K. Li, R. Pilloi, School of Pharmacy, Duquesne Univ., Pittsburgh, USA. The membrane-bound enzyme sterylsulfatase (STS, EC 3.1.6.2) catalyzes the hydrolysis of sulfuric acid esters of numerous neutral and phenolic steroids. STS activity is expressed in many human tissues where it is involved in the eutopic (e.g. in the placenta) or ectopic (e,g. in certain tumor cells) production of biologically active steroids from sulfoconjugated precursors. In order to study chemical prerequisites for high affinity binding towards the active site of the enzyme, several synthetic analogues of estrone sulfate characterized by an invariable 3-desoxyestrone (dE1) moiety but different substituents present at the 3-position were tested as STS lnhibitars. Using both human placental microsomes and a homogeneous STS preparation as the enzyme source and 35S-labeled dehydroepiandrosterone sulfate or estrone sulfate as substrates, the following order of inhibitory potencies was obtained: dE 1-3-SO2Cl -dE 1-3-OSO2CH3 > dE 1-3-SO2 F = dE 1-3-SO3> dE 1-3-CH2SO3 dE1-3-SO2NH2 = dE1-3-SO2CH3. The sulfonyl chloride derivative completely inactivated the STS activity when preincubated with the enzyme, whereas the extent of inhibition by all other compounds did not vary with the preincubation time. As compared to the KM value of estrone sulfate, however, the Ki values of even the most potent inhibitors were about tenfold higher. Based on these findings it may be hypothesized that both an electronegative substituent at the sulfur atom (S-O-, S-CI, S-F) and an oxygen function in between the sulfur atom and the aromatic ring (as present in estrone sulfate or dE 1-3-OSO2CH 3) are necessary for high affinity binding towards the human sterylsulfatase.

Tetraphenylphosphonium bromide-catalyzed ‘Halex’ fluorination of chloroaryl sulfonyl chlorides

Halogen-exchange of chloroaryl sulfonylchloride derivatives with spray-dried potassium fluoride was found to proceed efficiently by employing tetraphenylphosphonium bromide as a catalyst. Subsequent desulfonylation of the fluoroaryl sulfonyl derivatives readily afforded fluoroaromatics under acidic condition.

Texas red, a hydrophilic, red-emitting flourophore for use with flourescein in dual parameter flow microfluorometric and fluorescence microscopic studies

The sulfonylchloride derivative of the red-emitting fluorophore, sulforhodamine 101, has been synthesized in order to provide a reagent for coupling to amino groups on proteins and other compounds, and it is now commercially available under the name “Texas Red”. Texas Red conjugates of antibodies and other proteins have been prepared in high protein yields; these conjugates retained their biological activities and were strongly fluorescent. The excitation and emission spectra of Texas Red conjugates are widely separated from those of molecules labeled with fluorescein isothiocyanate. Texas Red is therefore an excellent reagent for use in single or dual label flow microfluorometric and fluorescent microscopic studies.

Chlorosulfonation of 2‐arylimidazoles

AbstractThe chlorosulfonation of 2‐arylimidazoles was investigated; the resulting sulfonyl chloride derivatives were isolated and characterized as the corresponding sulfonamides. When the 2‐aryl substituent was 3,4‐dichlorophenyl or 3‐pyridyl, chlorosulfonation occurred only on the imidazole ring. The chlorosulfonation of 2‐(4‐chlorophenyl)imidazole was temperature dependent, yielding either a mono or disulfonamide after treatment with ammonia. The structure of this disulfon‐amide was determined from pmr spectra to be 2‐(4‐chloro‐3‐sulfamoyl)‐4(5)sulfamoylimidazole.

Microanalysis of anionic surfactants in waste water by infrared spectroscopy

Infrared spectroscopy was applied to identify and determine microamounts of anionic surfactants contained in sewage or river waters. The surfactants tested were linear alkylbenzene sulfonate (LAS), branched alkylbenzene sulfonate (ABS), alpha olefine sulfonate (AOS), fatty alcohol sulfate (AS) and fatty alcohol ethoxy sulfate (AES). Anionic surfactants in waters were extracted by chloroform as methylene blue complexes and sulfate type surfactants, i.e. AS and AES were then removed by subsequent hydrolysis. Residual sulfonate type surfactants were first released from methylene blue complexes by ion exchange technique and then changed to sulfonyl chloride derivatives for infrared spectroscopy. Key bands for the identification of sulfonate type surfactants are 640, 618 and 524 cm −1 for LAS, ABS and AOS, respectively. Sulfate type surfactants was calculated from the difference of methylene blue active substance contents before and after hydrolysis.

Reaction of trialkylborane. IV. Reaction of trialkylborane with aromatic sulfonyl chlorides (author's transl)

Reaction of trialkylborane (I or II) with aromatic sulfonyl chloride derivatives (III-VIII) caused reductive alkylation and afforded the corresponding alkyl aryl sulfides (IX-XX) with a small quantity of mercaptans and disulfides. In this reaction, the yield of alkyl aryl sulfide was considerably better than that in the reaction with diphenyl sulfide (XXII) or sulfenyl chloride (XXIII) under the same condition. In the case of cyclohexyl phenyl sulfone (XXIV), a small amount of alkyl aryl sulfide was obtained, and diphenyl sulfone (XXV) did not react with trialkylborane. Since the reaction of trialkylborane with aromatic sulfonyl chloride was inhibited in the presence of a radical scavenger such as iodine or galvinoxyl, this reaction was considered to include a radical reaction.