- Synthesis, structure and band gap of novel thiophene based conductive polymers
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A novel poly 3-(2-benzo thiazolyl) thiophene based conductive polymer have been synthesized and characterized using various experimental techniques. The structure and band gap (difference between Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital) for the above polymer have been calculated using oligomeric approach employing B3LYP/3-21G* method and semi-empirical AM1 and ZINDO methods. The calculated band gap for monomer, dimmer and trimmer has been plotted versus 1/N (where N is the number units). The value at 1/N= 0, is taken as the band gap of the polymer having long chain length. It is evident from the theoretical investigations, the band gap of poly 3-(2-benzothiazolyl) thiophene is 3.77 eV. It is possible to change the band gap by designed alteration in the thiophene framework. Copyright
- Radhakrishnan,Subramanian,Somanathan,Srinivasan,Ramasami
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- Efficient synthesis of benzothiazole derivatives by reaction of bis(2-aminophenyl) disulfides with aldehydes mediated by NaSH under microwave irradiation
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2-Substituted benzothiazoles were synthesized through condensation of bis(2-aminophenyl) disulfides with arylaldehydes catalyzed by inexpensive NaSH in PEG-300 and assisted by low energy microwave irradiation(25?W). Various 2-substitutedbenzothiazoles were obtained in moderate to high yields after simple post-reaction processing including adding distilled water, filtrating, and drying. Moreover, it was found that the S-S bond of the disulfide was reduced by NaSH and also by the intermediate benzothiazoline.
- Liu, Lei,Zhang, Fa,Wang, Hongliang,Zhu, Ning,Liu, Bo,Hong, Hailong,Han, Limin
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p. 464 - 468
(2017/04/03)
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- Synthesis of 2 - substituted benzothiazole derivatives
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The invention discloses a method of synthesizing a 2-substituted benzothiazole-type derivative, wherein the method includes a step of synthesizing the 2-substituted benzothiazole-type derivative with an aldehyde and a disulphide as raw materials under a combined effect of at least one from NaHCO3 and AcOH with a metal sulfide. The particular reaction is represented as follows, wherein the R comprises one or more from a hydrogen atom, a C1-C4 alkyl, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a cyan group and a nitryl group; the R' substituent group comprises at least one from a C1-C6 alkyl, a furan group, a thienyl group, a pyrryl group, a pridyl group and a substituted phenyl group. The method employs the raw material being stable and easy to obtain, and can quickly and conveniently synthesize the 2-substituted benzothiazole-type derivative at a high production yield.
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Paragraph 0103-0106
(2017/07/23)
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- Method for realizing green synthesis of 2-substituted benzothiazole derivatives
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The invention provides a method for realizing green synthesis of 2-substituted benzothiazole derivatives. The method comprises the following steps of: contacting aldehyde, o-amido aroma disulphide and metal sulfide by taking water as a solvent in the present of CO2, so as to obtain 2-substituted benzothiazole derivatives. Compared with the prior art, the method has the characteristics that o-amido aroma disulphide and multiple types of aldehyde react under the effects of water and CO2, so that the 2-substituted benzothiazole derivatives are rapidly and efficiently synthetized, and the used raw materials are easily obtained and low in cost; the synthesis method has the advantages of simplicity and convenience in operation, short steps, high yield, easiness for product purification, environmental friendliness and the like.
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Paragraph 0108; 0109; 0110; 0111; 0112; 0013; 0114; 0115
(2016/10/10)
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- Novel synthesis of benzothiazole by self-redox tandem reaction of disulfide with aldehyde
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A novel methodology for the preparation of benzothiazole derivatives via the reaction of ortho-anilino disulfides with aryl and heteroaryl aldehydes catalyzed by Na2S·9H2O has been developed. The reaction mechanism was investigated by LC-MS and 1H NMR. The disulfide was cleaved firstly by the interchange reaction of the disulfide and metal sulfide, and the resulting thiol reacted in situ with the aldehyde to form the corresponding benzothiazoline. Subsequently, the intermediate benzothiazoline reduced the disulfide to thiol and it was oxidized to benzothiazole. The excess benzothiazoline was oxidized by air and both halves of the disulfide were ultimately converted to the desired benzothiazole.
- Liu, Bo,Zhu, Ning,Hong, Hailong,Han, Limin
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p. 9287 - 9292
(2015/11/27)
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- Trichloroisocyanuric Acid/Triphenylphosphine-Mediated Synthesis of Benzimidazoles, Benzoxazoles, and Benzothiazoles
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A new and efficient method for preparation of benzimidazoles, benzoxazoles, and benzothiazoles from reactions of different carboxylic acids with o-phenylenediamine, o-aminophenol, and o-aminothiophenol in the presence of triphenylphosphine/trichloroisocyanuric acid system is presented. The desired products have been characterised on the basis of spectral (infrared, NMR, mass spectrometry) data, and the mechanism of their formation is proposed. The remarkable advantages are the inexpensive and readily available reagent, simple procedure, mild conditions, and good-to-excellent yields.
- Rezazadeh, Soodabeh,Akhlaghinia, Batool,Razavi, Nasrin
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p. 145 - 155
(2015/05/05)
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- Elemental sulfur mediated decarboxylative redox cyclization reaction of o -chloronitroarenes and arylacetic acids
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A decarboxylative redox cyclization strategy has been developed for the synthesis of 2-substituted benzothiazoles by the reaction of o-chloronitroarenes and arylacetic acids in the presence of elemental sulfur/N-methylmorpholine under metal- and solvent-free conditions.
- Guntreddi, Tirumaleswararao,Vanjari, Rajeshwer,Singh, Krishna Nand
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supporting information
p. 976 - 978
(2015/03/30)
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- Synthesis and structure-activity relationship of 4-(1,3-benzothiazol-2-yl)- thiophene-2-sulfonamides as cyclin-dependent kinase 5 (cdk5)/p25 inhibitors
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4-(1,3-Benzothiazol-2-yl)thiophene-2-sulfonamide (4a) was found to be a moderately potent inhibitor of cyclin-dependent kinase 5 (cdk5) from a HTS screen. The synthesis and SAR around this hit is described. The X-ray coordinates of ligand 4a with cdk5 are also reported, showing an unusual binding mode to the hinge region via a water molecule.
- Malmstroem, Jonas,Viklund, Jenny,Slivo, Can,Costa, Ana,Maudet, Mickael,Sandelin, Catrin,Hiller, Goesta,Olsson, Lise-Lotte,Aagaard, Anna,Geschwindner, Stefan,Xue, Yafeng,Vasaenge, Mervi
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p. 5919 - 5923
(2012/11/07)
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- Nickel-catalyzed C-H arylation of azoles with haloarenes: Scope, mechanism, and applications to the synthesis of bioactive molecules
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Novel nickel-based catalytic systems for the C-H arylation of azoles with haloarenes and aryl triflates have been developed. We have established that Ni(OAc)2/bipy/LiOtBu serves as a general catalytic system for the coupling with aryl bromides and iodides as aryl electrophiles. For couplings with more challenging electrophiles, such as aryl chlorides and triflates, the Ni(OAc)2/dppf (dppf=1,1′-bis(diphenylphosphino)ferrocene) system was found to be effective. Thiazoles, benzothiazoles, oxazoles, benzoxazoles, and benzimidazoles can be used as the heteroarene coupling partner. Upon further investigation, we discovered a new protocol for the present coupling using Mg(OtBu)2 as a milder and less expensive alternative to LiOtBu. Attempts to reveal the mechanism of this nickel-catalyzed heterobiaryl coupling are also described. This newly developed methodology has been successfully applied to the syntheses of febuxostat (a xanthine oxidase inhibitor that is effective for the treatment of gout and hyperuricemia), tafamidis (effective for the treatment of TTR amyloid polyneuropathy), and texaline (a natural product having antitubercular activity). Copyright
- Yamamoto, Takuya,Muto, Kei,Komiyama, Masato,Canivet, Jerome,Yamaguchi, Junichiro,Itami, Kenichiro
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supporting information; experimental part
p. 10113 - 10122
(2011/10/08)
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- Nickel-catalyzed biaryl coupling of heteroarenes and aryl halides/triflates
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Ni-based catalytic systems for the arylation of heteroarenes with aryl halides and triflates have been established. Ni(OAc)2/bipy is a general catalyst for aryl bromides/iodides, and Ni(OAc)2/dppf is effective for aryl chlorides/triflates. Thiazole, benzothiazole, oxazole, benzoxazole, and benzimidazole are applicable as heteroarene coupling partners. A rapid synthesis of febuxostat, a drug for gout and hyperuricemia, is also demonstrated.
- Canivet, Jerome,Yamaguchi, Junichiro,Ban, Ikuya,Itami, Kenichiro
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supporting information; experimental part
p. 1733 - 1736
(2009/08/15)
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- One-pot synthesis of 2-aryl-and 2-alkylbenzo-thiazoles under microwave irradiation
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Eco-friendly direct solvent-free reactions of o-aminothiophenol and aromatic or aliphatic β-keto esters with microwave irradiation produced 2-substituted benzothiazoles in excellent yield. Experiments that compared microwave irradiation to conventional heating methods showed that the former gives the 2-substituted benzothiazoles faster and in higher yields. The formation of the titled compounds probably involves the nucleophilic addition of the thiol group to the keto group of the β-keto ester with subsequent elimination of ethyl acetate from the resulting adduct. The adduct then undergoes an intramolecular addition of the o-amino group to the carbonyl group to give an adduct from which water is eliminated to afford the 2- substituted benzothiazoles.
- Kamila, Sukanta,Zhang, Hongming,Biehl, Edward R.
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p. 2119 - 2126
(2007/10/03)
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- An efficient palladium catalyzed synthesis of 2-arylbenzothiazoles
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A novel and convergent palladium catalyzed synthesis of 2-arylbenzothiazoles has been investigated. The key step in the synthesis is a Suzuki biaryl coupling of 2-bromobenzothiazole with aryl boronic acids to provide a variety of 2-arylbenzothiazole derivatives in good yield. The synthetic utility of this methodology is demonstrated by the synthesis of 2-(4-aminophenyl)-6-methoxybenzothiazole, a PET probe precursor for the in vivo imaging of Alzheimer's disease.
- Majo, Vattoly J.,Prabhakaran, Jaya,Mann, J. John,Kumar, J. S. Dileep
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p. 8535 - 8537
(2007/10/03)
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- Synthesis and Fluorescent Properties of Some New Unsymmetric bis-Benzothiazolyl Furans and Thiophenes
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Some new mono- and bis-benzothiazolyl compounds with furan and thiophene nuclei were synthesized by multistep reactions from the corresponding furan and thiophene aldehydes.The data obtained from emission spectra show a large influence of the benzothiazol
- Racane, L.,Tralic-Kulenovic, V.,Karminski-Zamola, G.,Fiser-Jakic, L.
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p. 1375 - 1382
(2007/10/03)
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