Synthesis of 1-aryl-5-chloro-3-(phenylsulfonyl)pyrazol-4-ols from 1,1-dichloro-3-phenylsulfonyl-2-propanone

1,1-Dichloro-3-phenylsulfonyl-2-propanone was treated with arenediazonium chlorides to give 1-arylhydrazono-3,3-dichloro-1-phenylsulfonyl-2-propanones, which were cyclized to 1-aryl-5-chloro-3-(phenylsulfonyl)pyrazol-4-ols on treatmemt with base.     

Regioselective 1,3-Dipolar Cycloaddition Reactions of Unsymmetrical Münchnones (1,3-Oxazolium-5-olates) with 2- and 3-Nitroindoles. A New Synthesis of Pyrrolo[3,4-b]indoles

The unsymmetrical mesoionic münchnones 13 (3-benzyl-2-methyl-4-phenyl-1,3-oxazolium-5-olate) and 14 (3-benzyl-4-methyl-2-phenyl-1,3-oxazolium-5-olate) react with the N-protected 2- and 3-nitroindoles 1 (ethyl 2-nitroindole-1-carboxylate), 6 (3-nitro-1-(phenylsulfonyl)indole), and 17 (ethyl 3-nitroindole-1-carboxylate) in refluxing THF to afford in good to excellent yields the pyrrolo[3,4-b]indoles 15 (2-benzyl-1-methyl-3-phenyl-4-carboethoxy-2,4-dihydropyrrolo[3,4-b]indole), 16 (2-benzyl-3-methyl-1-phenyl-4-carboethoxy-2,4-dihydropyrrolo[3,4-b]indole), 18 (2-benzyl-1-methyl-3-phenyl-4-(phenylsulfonyl)-2,4-dihydropyrrolo[3,4-b]indole), and 19 (2-benzyl-3-methyl-1-phenyl-4-(phenylsulfonyl)-2,4-dihydropyrrolo[3,4-b]indole). In several cases the regiochemistry, which is opposite to that predicted by FMO theory, is very high and leads essentially to a single pyrrolo[3,4-b]indole; e.g., 6+13→19 in 74% yield.     

Zur Synthese sulfonierter Derivate von 4-Amino-1,3-dimethylbenzol und 2-Amino-1,3-dimethylbenzol

Syntheses of Sulfonated Derivatives of 4-Amino-1, 3-dimethylbenzene and 2-Amino-1, 3-dimethylbenzene Direct sulfonation of 4-amino-1, 3-dimethylbenzene (1) and sulfonation of 4-nitro-1,3-dimethylbenzene ( 4 ) to 4-nitro-1,3-dimethylbenzene-6-sulfonic acid ( 3 ) followed by reduction yield 4-amino-1,3-dimethylbenzene-6-sulfonic acid ( 2 ). The isomeric 5-sulfonic acid ( 5 ) however is prepared solely by baking the acid sulfate salt of 1 . Reaction of sulfur dioxide with the diazonium chloride derived from 2-amino-4-nitro-1,3-dimethylbenzene ( 7 ) leads to 4-nitro-1,3-dimethylbenzene-2-sulfonyl chloride ( 8 ), which is successively hydrolyzed to 4-nitro-1,3-dimethylbenzene-2-sulfonic acid ( 9 ) and reduced to 4-amino-1, 3-dimethylbenzene-2-sulfonic acid ( 6 ). Treatment of 4-amino-6-bromo-1,3-dimethylbenzene ( 12 ) and 4-amino-6-chloro-1, 3-dimethylbenzene ( 13 ), the former obtained by reduction of 4-chloro-6-nitro-1,3-dimethyl-benzene ( 10 ) and the latter from 4-chloro-6-nitro-1, 3-dimethylbenzene ( 11 ), with oleum yield 4-amino-6-bromo-1,3-dimethylbenzene-2-sulfonic acid ( 14 ) and 4-amino-6-chloro-1,3-dimethylbenzene-2-sulfonic acid ( 15 ) respectively; subsequent carbon-halogen hydrogenolyses of 14 and 15 lead also to 6 (Scheme 1). Baking the acid sulfate salt of 2-amino-1, 3-dimethylbenzene ( 17 ) gives 2-amino-1, 3-dimethylbenzene-5-sulfonic acid ( 16 ), whereas the isomeric 4-sulfonic acid ( 18 ) can be prepared by either of the following three possible pathways: Sulfonation of 2-nitro-1,3-dimethylbenzene ( 20 ) to 2-nitro-1,3-dimethylbenzene-4-sulfonic acid ( 21 ) followed by reduction or sulfonation of 2-acetylamino-1,3-dimethylbenzene ( 19 ) to 2-acetylamino-1,3-dimethylbenzene-4-sulfonic acid ( 22 ) with subsequent hydrolysis or direct sulfonation of 17 . Further sulfonation of 18 yields 2-amino 1,3-dimethylbenzene-4,6-disulfonic acid ( 23 ), the structure of which is independently confirmed by reduction of unequivocally prepared 2-nitro- 1,:3-dimethylbenzene-4,6-disulfonic acid ( 24 )(Scheme 2).     

5-nitro-5-(1′-cyclohexenyl)- and 5-nitro-5-(1′-cycloheptenyl)-3-benzyl- and 3-cyclohexyl tetrahydro-1,3-oxazines

1-(Cyclohexenyl- and 1-cycloheptenylnitromethane have been used as starting substances to yield 2-nitro-2-(1′-cyclohexenyl)- and 2-nitro-2-(1′-cycloheptenyl)-propanediol-1,3 (B) respectively. By reacting them with formaldehyde and benzylamine or formaldehydes and cyclohexylamine, derivatives of tetrahydro-1,3-oxazine (B) have been prepared. Acid hydrolysis of tetrahydro-1,3-oxazine derivatives results in the formation of 3-hydroxy-2-nitro-2-(1′-cyclohexenyl)- and 3-hydroxy-2-nitro-2-(1′-cycloheptenyl)-propylamine derivatives (E). Both aminoalcohols (E) react with formaldehyde to again yield tetrahydro-1,3-oxazine derivatives (C).

Infra-red spectra of C and E and their hydrochlorides D and F were examined and structure assignments made of the principal bands.     

One—Pot Reaction of Aldehydes,α—Haloketones and （Phenylsulfonyl） acetonitrile Promoted by SmI3

One-pot reaction of aldehydes,α-haloketones and (phenylsulfonyl) acetonitrible promotes by SmI3 proceeded smoothyl to give 1-cyano-1-phenylsulfonyl-2-aryl-3-aroyl-propane derivatives in moderate good yields.     

Nitropyrazoles 22. On reactivity of 3,5-dinitro-4-(phenylsulfonyl)pyrazole and its N-methyl derivative

3,5-Dinitro-4-(phenylsulfonyl)pyrazole (5) obtained by oxidation of 3,5-dinitro-4-(phenylthio)pyrazole with 30% H₂O₂ in AcOH was involved into nucleophilic substitution reaction with thiophenol, which proceeded with substitution of the phenylsulfonyl group at position 4. N-Methyl-3,5-dinitro-4-(phenylsulfonyl)pyrazole obtained by methylation of 5 with dimethyl sulfate was involved into nucleophilic substitution reaction with thiophenol, p-bromophenol, and morpholine with the regioselective substitution of the nitro group at position 5 to form 5-R-3-nitro-4-(phenylsulfonyl)pyrazoles.     

α′-苯磺酰基-α,β-不饱和酮与开链二烯烃的不对称催化环加成反应

在手性金属钛催化剂存在下 ,研究了α′ 苯磺酰基 α ,β 不饱和酮与开链二烯的不对称催化环加成反应 ,讨论了α′ 苯磺酰基 α ,β 不饱和酮与开链二烯的反应活性和对映选择性 ,以高的收率和光学纯度合成了环己烯衍生物 ,并对部分产物的构型进行了鉴定     

An ecofriendly approach to the synthesis of 2-imino- and 2-oxo-3-phenylsulfonyl-2H-chromenes

An efficient synthesis for 2-imino-3-phenylsulfonyl-2H-chromenes was developed from the Knoevenagel condensation of (phenylsulfonyl)acetonitrile and salicylaldehydes in aqueous sodium carbonate solution, at room temperature. Hydrolysis in aqueous HCl, at 80 °C, led to the formation of the corresponding 2-oxo-3-phenylsulfonyl-2H-chromenes, also isolated in excellent yields.     

New method for the synthesis of indenes

A new two-step method was developed for the synthesis of 2-sulfonyl-substituted indenes from aromatic aldehydes. The reactions of 1-phenylsulfonyl-1-(trimethylsilyl)ethylene with ortho-lithiated derivatives of aromatic and heteroaromatic aldehydes afford conjugate addition products whose subsequent cyclization gives substituted 2-sulfonylindenes in preparative yields. The reactions of 2-(phenylsulfonyl)indenes with Grignard reagents were studied. It was shown that the sulfonyl group can be replaced in the presence of iron(iii) acetylacetonate.     

Reaction of 3,4-disubstituted 1,2,5-oxadiazole 2-oxides with dipolarophiles : Substituent and solvent effect on the reaction courses

A variety of symmetrically or unsymmetrically 3,4-disubstituttd furoxans such as dicyano, dialkyl, diacyl, bis(phenylsulfonyl), N.N'-dialkyldicarbamoyl, 3(or 4)-methyl-4(or -3)-phenyl(or nitro, ethoxy, phenoxy, phenylthio, pyrrolidinyl, phenylsulfonyl), 3(or 4)-ethyl-4(or -3)phcnyl, and 3(or 4)-ethoxy-4(or -3)-phenylsulfonylruroxan reacted with dipolarophiles in toluene or xylene at the refluxing temperature to give nitrone-type 1,3-dipolar cycloadducts, 5-substituted 1-aza-2,8-dioxabicyclo-[3.3.0]octanes and/or 3-substituted 2-isoxazoline 2-oxides. On the other hand, some of the furoxans gave 2-isoxazolines via nitrile oxide 1,3-dipolar cycloaddition in a toluene (or xylene)-DMF solvent at the refluxing temperature.     

From beta-nitrothiophenes to ring-fused nitrobenzenes: an overall ring-enlargement process via a facile, aromatization-driven, thermal 6pi electrocyclization

[reaction: see text] In prosecution of previous work on the thermal cyclization of 1-aryl-4-methanesulfonyl-2-nitro-3-phenylsulfonyl-1,3-butadienes (7), the 3-unsubstituted derivatives 8, deriving from the initial ring opening of 3-nitrothiophene (2), have been likewise found herein to undergo cyclization, followed by aromatization, in analogous mild experimental conditions, leading to the ring-fused homo- or heteroaromatic nitro derivatives 10. The concerted electrocyclic nature of the process is strongly supported by the outcome of tests based on the variation of the polarity of the solvent or of the electron density on the aryl of 8. Thus, the successful application of the process to the non-phenylsulfonyl-activated 8 significantly widens the scope of a synthetically valuable overall ring-opening/ring-closing procedure from nitrothiophenes. Support to the recently renewed interest in thermal 6pi electrocyclizations as a tool for the construction of the benzene ring is furthermore provided.     

Regioselective synthesis of functionalized 4-nitro- and 4-amino-phenols based on formal [3+3] cyclocondensations of 3-ethoxy-2-nitro-2-en-1-ones with 1,3-bis(silyloxy)-1,3-butadienes

Functionalized 4-nitro- and 4-aminophenols were regioselectively prepared based on [3+3] cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-ethoxy-2-nitro-2-en-1-ones.     

Nucleophilic amination of 2-iodo-3-nitro-1-(phenylsulfonyl)indole

The reaction of 2-iodo-3-nitro-1-(phenylsulfonyl)indole (2) with amines affords the corresponding 2-amino-3-nitroindoles in excellent yields via nucleophilic aromatic substitution.     

Formation of 2‐(Phenylsulfonyl)resorcinols (=2‐(Phenylsulfonyl)benzene‐1,3‐diols) from Symmetrically Substituted Maleic Anhydrides (=Furan‐2,5‐diones)

Treatment of symmetrically substituted maleic anhydrides (=furan‐2,5‐diones) 6 with lithium (phenylsulfonyl)methanide, followed by methylation of the adduct with MeI/K₂CO₃ in acetone, give the corresponding 4,5‐disubstituted 2‐methyl‐2‐(phenylsulfonyl)cyclopent‐4‐ene‐1,3‐diones 8 (Scheme 3). Reaction of the latter with lithium (phenylsulfonyl)methanide in THF (?78°) and then with 4 mol‐equiv. BuLi (?5° to r.t.) leads to 5,6‐disubstituted 4‐methyl‐2‐(phenylsulfonyl)benzene‐1,3‐diols 9 (Scheme 4).     

Preparation and characterization of SbCl<Subscript>5</Subscript> supported on coconut shell as nanocatalyst for the synthesis of novel 2-amino-3-phenylsulfonyl-4-aryl-4<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">h</Emphasis>]chromens

Pentachlorid antimony supported on coconut shell as an efficient and novel catalyst for one-pot synthesis of 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromen through three-component condensation of \( \alpha \)- naphtol, arylaldehydes and phenylsulfonyl (acetonitrile). Nanocatalyst pentachloride antimony supported on coconut shell was manufactured and characterized by FT-IR, TGA/DTG, XRD, EDX, FESEM and TEM techniques. The present method has advantages such as high activity, high reaction rate, recoverability of nanocatalyst, a simple experimental procedure, without any using of hazardous organic solvents under green conditions.     

A new route to benzo[4,5]cyclohepta[1,2-b]naphthalenes: synthesis of radermachol

[formula: see text] Condensation of 3-phenylsulfonyl-1,3-isobenzofuranone (3) with benzocyclohept-6,7-en-5-ones such as 4 and 15 provides a straightforward, general method for synthesis of functionalized benzo[4,5]cyclohepta[1,2-b]naphthalenes (e.g., 5 and 16). This finding was used to achieve a brief and efficient preparation of 6,7-benzo-3,4-(1,4-dimethoxy-2,3-naphtho)-1,5-dioxosuberane (2), an established intermediate to the naturally occurring red pigment radermachol (1).     

辅酶Q10的合成

以2,3,4,5-四甲氧基甲苯为原料, 经溴化、生成格氏试剂后在碘化亚铜存在下与(E)-4-氯-2-甲基-1-苯磺酰基-2-丁烯缩合得到合成辅酶Q10的关键中间体6-(E-3'-甲基-4'-苯磺酰基-2'-丁烯基)-2,3,4,5-四甲氧基甲苯. 此中间体与茄尼基溴缩合、脱砜基化反应和氧化三步反应, 最终制得标题化合物辅酶Q10, 以2,3,4,5-四甲氧基甲苯计总收率达31.3%.     

α’-苯磺酰基-α，β-不饱和酮与开链二烯烃的不对称催化环加成反应

在手性金属钛催化剂存在下，研究了α’—苯磺酰基—α，β-不饱和酮与开 链二烯的不对称催化环加成反应，讨论了α’—苯磺酰基—α，β—不饱和酮与开 链二烯的反应活性和对映选择性，以高的收率和光学纯度合成了环己烯衍生物，并 对部分产物的构型进行了鉴定．     

Synthesis of 3,4-dihydro-2H-pyrans by hetero-Diels-Alder reactions of functionalized alpha,beta-unsaturated carbonyl compounds with N-vinyl-2-oxazolidinone

Cycloadditions of 3-aryl-2-benzoyl-2-propenenitriles and 3-phenylsulfonyl-3-buten-2-one to N-vinyl-2-oxazolidinone proceed regio- and diastereoselectively yielding cis and trans diastereoisomers of 4-aryl-3,4-dihydro-2-(2-oxo-3-oxazolidinyl)-2H-pyrans in 37-65% yield. Cycloadducts cis- were the major products. Reaction of 5-arylidene-1,3-dimethylbarbituric acids with dienophile afforded mixtures of 2H-pyrano[2,3-d]pyrimidine-2,4(3H)-diones trans and products resulted from an elimination of 2-oxazolidinone, in 50-52% yield. To confirm the experimental results, semiempirical AM1 and PM3 calculations of frontier orbital energies have been performed.     

Reaction of 2-formyl-1,3-cyclanediones with N,N′-substituted 1,1-diamino-2-nitroethylenes

Reaction of 2-formyldimedone and 2-formyl-1,3-indanedione with 1,1-di(2-hydroxyethylamino)- and 1,1-di(4-morpholyl)-2-nitroethylenes produces 2-[3,3-di(2-hydroxyethylamino)-2-nitroprop-2-en-1-ylidene]- and 2-[3,3-di(4-morpholyl)-2-nitroprop-2-en-1-ylidene]-5,5-dimethyl-1,3-cyclohexanediones and the 1,3-indanediones, respectively. The reaction of the same 2-formyl-1,3-cyclanediones with 2-nitromethyleneimidazolidine yields 8,8-dimethyl-4-nitro-6-oxo-1,2,3,6,7,8-hexahydroimidazo[1,2-a]quinoline and 4-nitro-6-oxo-1,2-dihydro-6H-imidazo[1,2-c]-4-azafluorene.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lanet.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 330–333, March, 1999.