Reaction Of Chlorosulfonyl Isocyanate Research Articles

The (±)-6-Aza[1.0]triblattane Skeleton: Contraction beyond the Wilder-Culberson Ring System.

Synthesis of the 6-aza[1.0]triblattane skeleton and the unexpected construction of the 7-azatetracyclo[4.2.1.02,5.03,7]nonane framework are reported, as inspired by the Wilder-Culberson 1-aza[1.1]triblattane ring system. The key steps to assess the 6-aza[1.0]triblattane include accessing the 1,6-cycloaddition product from reaction of chlorosulfonyl isocyanate with cyclohept-1,3,5-triene followed by intramolecular electrocyclization and aminium radical cyclization.

Synthesis, anticancer, antimicrobial, anti-tuberculosis and molecular docking of heterocyclic N-ethyl-N-methylbenzenesulfonamide derivatives

A new series of chlorosulfonylcarbamate and urea heterocyclic benzenesulfonamides derivatives were synthesized to study the biological activities, via the reaction of chlorosulfonylisocyanate (CSI) on active heterocyclic N-ethyl-N-methylbenzenesulfonamide derivatives containing hydroxy (OH) and/or amino (NH and NH2) groups. The products were obtained in one pot short reaction times, high yields and high purities. The structures of the new prepared products were identified by elemental analysis, IR, 1H NMR, 13C NMR and MS spectral data. All the prepared products were investigated as in-vitro antitumor activity (CACO, A549, HEP-2), as in-vitro antimicrobial agents (Gram + and Gram -), as antifungal and as anti-tuberculosis agents. The effect of addition of chlorosulfonylcarbamate Cl–SO2–NH–CO–O- and urea Cl–SO2–NH–CO–N- groups was studied. The molecular docking studies of the prepared compounds using the Molecular Operating Environment (MOE) demonstrate that some new compounds are good inhibitors of dihydrofolate reductase (DHFR).

Crystal Structure and Vibrational Spectra of ClSO2NHC(O)F

The reaction of chlorosulfonyl isocyanate (ClSO2NCO) with anhydrous hydrogen fluoride (aHF) leads to the formation of ClSO2NHC(O)F. The title compound with a melting point of –38 °C is characterized by vibrational spectroscopy and a single crystal structure analysis. It crystallizes in the tetragonal space group I41/a with 16 formula units per unit cell. a = 11.1115(2) Å, c = 16.5654(6) Å. The experimental data are supported by quantum‐chemical calculations on the PBE1PBE/6‐311G(3pd,3df) level of theory.

ChemInform Abstract: Improved Synthetic Utility of a Sluggish Electrophile: Reaction of Chlorosulfonyl Isocyanate with Unreactive and Reactive Alkenes.

AbstractThe equilibrium between two separate reactants and a complex or SET intermediate formed by them shifts towards the unimolecular intermediate between ‐15 and 25°, therefore, the efficiency of the electrophile (II) is improved under the reaction conditions.

Improved Synthetic Utility of a Sluggish Electrophile: Reaction of Chlorosulfonyl Isocyanate with Unreactive and Reactive Alkenes

Chlorosulfonyl isocyanate (CSI) is a sluggish electrophile in reactions with electron-deficient alkenes or with many monofluoroalkenes. The efficiency of these reactions is improved at temperatures between –15 and 25 °C because, at these temperatures, CSI and the alkene are in equilibrium with an intermediate. A unimolecular reaction of the intermediate at a temperature between –15 and 25 °C is more efficient than the bimolecular reaction of the dissociated reagents above room temperature. This finding provides a method for improving the reactions of CSI with unreactive alkenes.

Kinetic Studies on the Reaction of Chlorosulfonyl Isocyanate with Monofluoroalkenes: Experimental Evidence for Both Stepwise and Concerted Mechanisms and a Pre-equilibrium Complex on the Reaction Pathway

Chlorosulfonyl isocyanate (CSI) is reported to react with hydrocarbon alkenes by a stepwise dipolar pathway to give N-chlorosulfonyl-β-lactams that are readily reduced to β-lactams. Substitution of a vinyl hydrogen for a vinyl fluorine changes the dynamics for reaction with CSI so that a concerted pathway is favored. Rate constants were measured for reactions of CSI with monofluoroalkenes and some hydrocarbon alkenes. Activation parameters for two hydrocarbon alkenes and two monofluoroalkenes support this change in mechanism. A plot generated from the natural log of rate constants vs ionization potentials (IP) indicates that fluoroalkenes with IP values >8.9 eV react by a concerted process. Electron-rich monofluoroalkenes with IP values <8.5 eV were found to react by a single-electron transfer (SET) pathway. Hydrocarbon alkenes were also found to react by this dipolar stepwise SET intermediate rather than the previously accepted stepwise dipolar pathway. Data support a pre-equilibrium complex on the reaction pathway just before the rate-determining step of the concerted pathway and a SET intermediate for the stepwise reactions. When the reactions are carried out at lower temperatures, the equilibrium shifts toward the complex or SET intermediate enhancing the synthetic utility of these reactions. Kinetic data also support formation of a planar transition state rather than the orthogonal geometry as reported for ketene [2 + 2] cycloadditions.

Reaction of Chlorosulfonyl Isocyanate with Fluorosubstituted Alkenes: Evidence of a Concerted Pathway

Concerted reactions are indicated for the electrophilic addition of chlorosulfonyl isocyanate with monofluoroalkenes. A vinyl fluorine atom on an alkene raises the energy of a stepwise transition state more than the energy of the competing concerted pathway. This energy shift induces CSI to react with monofluoroalkenes by a one-step process. The low reactivity of CSI with monofluoroalkenes, stereospecific reactions, the absence of 2:1 uracil products with neat fluoroalkenes, and quantum chemical calculations support a concerted pathway.

ChemInform Abstract: A Highly Stereoselective Synthesis of the 1β-Methylcarbapenem Key Intermediate from (R)-3-Hydroxybutyric Acid.

Abstract (3R,4R)-4-Acetoxy-3-[(R)-1-(formyloxy)ethyl]-2-azetidinone 6 could be prepared highly stereoselectivity from (R)-3-hydroxybutyric acid by employing the [2+2]-cycloaddition reaction of chlorosulfonyl isocyanate with the 2H,4H-1,3-dioxin derivative and the Baeyer-Villiger reaction accompanying novel cleavage of the acetal moiety. The Reformatsky reaction of 6 with sterically crowded 3-(2-bromopropionyl)-2-oxazolidone derivatives readily afforded the title key intermediate after sequential chemical manipulations.

ChemInform Abstract: Cycloaddition of Chlorosulfonyl Isocyanate with Arylmethylenemalonaldehydes.

Abstract The reaction of chlorosulfonyl isocyanate with arylmethylenemalonaldehydes afforded the fused 1,3-oxazin-2-one derivatives.

Synthesis of β-Lactams Bearing Functionalized Side Chains from a Readily Available Precursor

The reaction of chlorosulfonyl isocyanate (CSI) with alkenes provides beta-lactams in quantity, and the products have frequently been used for ring-opening polymerization to generate nylon-3 materials. Prior uses of this approach have focused almost entirely on beta-lactams with purely hydrocarbon substitutents. We show how a variety of beta-lactams bearing protected polar substituents can be generated from CSI-derived building blocks.

CHLOROSULFONATION OF SOME CRISSCROSS CYCLOADDUCTS FROM ISOCYANATES AND DIARYL AZINES

Reaction of chlorosulfonyl isocyanate (1) with arylaldehyde azines (7) gave the 2:1 crisscross adducts (8);attempts to prepare a disulphonamide of 8a gave only a mixture of the monosulfamide 9 and the diureide 10. The latter with trichloromethanesulfenyl chloride afforded the derivative 12a. and with chlorosulfonic acid hydrazinodicarbonamide (11). The azine 7a with benzoyl isocyanate (2) gave the expected crisscross adduct 13. With thiobenzoyl isocyanate (3) however, both 7a and 7d gave the 1: 1 adducts (14). whereas 7c gave a different 2: 1 adduct (15). Treatment of 14a with 1 gave the ureide 16. With both methyl isocyanate (4) and phenyl isocyanate (S), 7a gave the expected crisscross adducts (17a and b), and 7c with 5 similarly gave 17c. When 7a was treated with 1 followed by aqueous potassium iodide, the diureide (10) was formed; concentrated nitric acid converted 10 into the triazolenone (18). Treatment of 18 with chlorosulfonic acid-thionyl chloride gave the sulfonyl chloride (19) which was characterised as the sulfonamides (20 a-d). Diarylsulfamoyl azines (21 a-f) with 1 and potassium iodide, gave the diureides 22 a-f. 4-Methoxy-3-sulfamoylbenzaldehydeazines (23 a-c) reacted with 3 to give the 1: I adducts 24 a-c, while 4-chlorosulfonylphenyl isocyanate (6) with benzaldehyde azine (7a) gave the bis-chlorosulfonyl adduct (25a). characterised as the diethylsulfonamide 25b. Attempted chlorosulfonation of the tetraphenyl cycloadduct 17b did not give the tetrasulfonyl chloride (although the reaction was successful with the more reactive rnethoxy adduct 17c); the tetrasulfonyl chloride (26a) was converted into 3 sulfonamides (26 b-d). The unsymmetrically-substituted diaryl azines (27) reacted with 1 and potassium iodide to yield the diureides 28 a-f. Analogous cycloadditions of 1 with several keto azines were unsuccessful. Selected compounds will be screened for medicinal and pesticidal activity; compounds 9,10 and 12a showed fungicidal activity against barley powdery mildew.

Reactions of Chlorosulfonyl Isocyanate with Thiazolines and Oxazolines: Formation of Thiazolo and Oxazolothiadiazines

Abstract 2-Alkylthiazolines and oxazolines undergo cyclization reaction with chlorosulfonyl isocyanate to give thiazole and oxazole fused thiadiazine derivatives.

Cycloaddition of chlorosulfonyl isocyanate with arylmethylenemalonaldehydes

The reaction of chlorosulfonyl isocyanate with arylmethylenemalonaldehydes afforded the fused 1,3-oxazin-2-one derivatives.

Heterocyclization Reactions of Chlorosulfonyl Isocyanate with Ethyl 3-Oxo-2-(arylhydrazono)butanoates

Reaction of chlorosulfonyl isocyanate with ethyl 3-oxo-2-(arylhydrazono)butanoates (1a-i) gave thiadiazolotriazinediones (3a-i) and thiatriazinothioxapyridazines (6a-i). Here a 1:2 reaction of the butanoate and CSI followed by cyclization is postulated

Chlorosulfonyl Isocyanate in Reaction with Allenylphosphonic Diamides

Abstract The reactions of chlorosulfonyl isocyanate (CSI) with a great number of unsaturated compounds have been thoroughly studied, but there exists no data concerning its reactivity towards unsaturated phosphorus compounds. In the present report we communicate the results of the reaction of CSI with 3,3-dialkylsubstituted allenylphosphonic diamides. The reaction of the diamides 1a-h with CSI runs at low temperature with a high chemoselectivity, only the C2C2double bond of the allenic system being attacked: Depending on the type of the R3N-group and on the size of R1, R2 only the azetidinone-2 derivatives 2a-h are formed or some side reactions also proceed.

ChemInform Abstract: A Novel Synthesis of the 1β-Methylcarbapenem Key Intermediate Employing the (2 + 2)Cycloaddition Reaction of Chlorosulfonyl Isocyanate with a 4H-1,3-Dioxin Derivative.

Abstract A highly stereoselective synthetic route to the title compound was explored by featuring the [2+2]-cycloaddition reaction of chlorosulfonyl isocyanate with the 4H-1,3-dioxin derivative readily obtainable from methyl (R)-3-hydroxybutyrate, the Baeyer-Villiger reaction resulting in novel cleavage of the acetal moiety, and the Reformatsky reaction with sterically crowded 3-(2-bromopropionyl)-2-oxazolidone derivatives.

Chlorosulfonyl Isocyanate in Reaction with Allenylphosphonic Diamides

Abstract The reactions of chlorosulfonyl isocyanate (CSI) with a great number of unsaturated compounds have been thoroughly studied, but there exists no data concerning its reactivity towards unsaturated phosphorus compounds. In the present report we communicate the results of the reaction of CSI with 3,3-dialkylsubstituted allenylphosphonic diamides. The reaction of the diamides 1a-h with CSI runs at low temperature with a high chemoselectivity, only the C2C2double bond of the allenic system being attacked: Depending on the type of the R3N-group and on the size of R1, R2 only the azetidinone-2 derivatives 2a-h are formed or some side reactions also proceed.

A One Pot Synthesis of 1-Substituted-1,2,3,7-tetrahydro-8-nitroimidazo [1,2-a] [1,2,6] thiadiazine-7 (1H) one-5,5-dioxides

Abstract Reaction of chlorosulfonyl isocyanate with nitroketene aminals of imidazolidines afforded acyclic intermediates which on treatment with diisopropylamine were smoothly transformed into the corresponding 1-substituted-1,2,3,7-tetrahydro-8-nitroimidazo [1,2-a] [1,2,6] thiadiazine-7 (1H) one-5, 5-dioxides.

Reaction of chlorosulfonyl isocyanate with nitrones: an efficient method for the synthesis of cyclic enamides and 2h-pyrroles

Reaction of chlorosulfonyl isocyanate (CSI) with nitrones (derived from cyclic conjugated ketones), 1 - 7 and 3,4-dihydro-2H-pyrrole-1-oxides, 15a - f ,-has been studied. Nitrones, 1 - 7 , react with CSI to form the enamidea, 8 , 10 - 14 , and the cyclil-amide, 9 , in yields ranging from 33 to 72 %. However, the 5,4-dihydro-2H-pyrrole-1-oxides, 15a - e , on reaction with CSI gave the 2H-pyrr-oles, 16a - e , in good yields. The 3,4-dihydro-2H-pyrrole-1-oxide, 15f , under similar experimental conditions gave the pyrrolidone, 17f , in 40% yield. Plausible mechanisms for the above mentioned rearrangement and conversions have been proposed with experimental evidences.

Rearrangement of nitrones to amides using chlor0sulfonyl isocyanate

Reaction of chlorosulfonyl isocyanate (CSI) with nitrones 1 a-n and 5 a,b has been studied. α, α, N-Triaryl nitrones 1 a-n react with CSI to form the N,N-diaryl arylamides 3 a-n and 4 i-n in good yields. In the case of α-H, α, N-diaryl nitrones 5 a,b however, two compounds viz., the rearranged product 11 a,b and the 1,4-dihydro tetrazines 10 a,b are formed. The effect of substituents on the rearrangement has been studied. It is found that the nature of the substituent has got a profound effect on the rearrangement. We have also noted that the rearrangement is independent of the syn or anti configurations of the nitrones.