17073-34-6Relevant articles and documents
A convenient method for the synthesis of 2-amino substituted aza-heterocycles from N,N′-disubstituted thioureas using TsCl/NaOH
Heinelt, Uwe,Schultheis, Daniela,J?ger, Siegfried,Lindenmaier, Marion,Pollex, Annett,Beckmann, Henning S.G.
, p. 9883 - 9888 (2004)
p-Toluenesulfonyl chloride (TsCl)/NaOH has been introduced as reagent combination for the synthesis of 2-amino-oxa- or 2-amino-thiazolidines from N-(2-hydroxyethyl)-thioureas, but its general application in heterocycle synthesis has not been investigated. In this paper the convenient and efficient synthesis of a variety of 2-amino-substituted 1-aza 3-(aza, oxo or thio) heterocycles of different substitution and ring sizes is described. The application of polymer-supported TsCl facilitates work-up and renders the reaction conditions very suitable for parallel or robot synthesis. Graphical Abstract
Environment-friendly and efficient synthesis of 2-aminobenzo-xazoles and 2-aminobenzothiazoles catalyzed by: Vitreoscilla hemoglobin incorporating a cobalt porphyrin cofactor
Li, Fengxi,Li, Zhengqiang,Su, Jiali,Wang, Chunyu,Wang, Ciduo,Wang, Lei,Xu, Yaning,Zhao, Nan
, p. 8047 - 8052 (2021/11/01)
In this study, an environment-friendly and efficient artificial Vitreoscilla hemoglobin (VHb) for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles has been reported. We demonstrate an expression-based porphyrin substitution strategy to produce VHb containing cobalt porphyrin instead of native hemin, which can catalyze the oxidative cyclization of corresponding 2-aminobenzoxazoles and 2-aminobenthiazoles with up to 97% yield and 4850 catalytic turnovers in water under aerobic conditions. Hence, we provide a green and mild method for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles. In addition, we indicate the value of porphyrin ligand substitution as a strategy to tune and enhance the catalytic properties of hemoproteins in non-natural reactions.
Pharmacomodulations of the benzoyl-thiosemicarbazide scaffold reveal antimicrobial agents targeting D-alanyl-D-alanine ligase in bacterio
Ameryckx, Alice,Pochet, Lionel,Wang, Gang,Yildiz, Esra,Saadi, Bouazza Es,Wouters, Johan,Van Bambeke, Fran?oise,Frédérick, Rapha?l
supporting information, (2020/06/03)
D-Alanyl-D-alanine ligase (Ddl) is a validated and attractive target among the bacterial enzymes involved in peptidoglycan biosynthesis. In the present work, we investigated the pharmacomodulations of the benzoylthiosemicarbazide scaffold to identify new Ddl inhibitors with antibacterial potency. Five novel series of thiosemicarbazide analogues, 1,2,4-thiotriazole-3-thiones, 1,3,4-thiadiazoles, phenylthiosemicarbazones, diacylthiosemicarbazides and thioureas were synthesized via straightforward procedures, then tested against Ddl and on susceptible or resistant bacterial strains. Among these, the thiosemicarbazone and thiotriazole were identified as the most promising scaffolds with Ddl inhibition potency in the micromolar range. Antimicrobial evaluation of salicylaldehyde-4(N)-(3,4-dichlorophenyl) thiosemicarbazone 33, one of the best compounds in our study, revealed interesting antimicrobial activities with values of 3.12–6.25 μM (1.06–2.12 μg/mL) against VRE strains and 12.5–25.0 μM (4.25–8.50 μg/mL) towards MRSA and VRSA strains. A detailed mechanistic study was conducted on the Ddl inhibitors 4-(3,4-dichlorophenyl)-5-(2-hydroxyphenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 20 and compound 33, and revealed a bactericidal effect at 5 × MIC concentration after 7 h and 24 h, respectively, and a bacteriostatic effect at 1 × MIC or 2 × MIC without any sign of bacterial membrane disruption at these lower concentrations. Finally, 20 and 33 were proved to target Ddl in bacterio via intracellular LC-MS dosage of D-Ala, L-Ala and D-Ala-D-Ala. Although, at this stage, our results indicate that other mechanisms might be involved to explain the antimicrobial potency of our compounds, their ability to inhibit the growth of strains resistant to usual antibiotics, as well as strains that express alternative ligases, sets the stage for the development of new antimicrobial agents potentially less sensitive to resistance mechanisms.
Potassium Periodate Mediated Oxidative Cyclodesulfurization toward Benzofused Nitrogen Heterocycles
Duangkamol, Chuthamat,Pattarawarapan, Mookda,Phakhodee, Wong
, p. 1981 - 1990 (2020/07/03)
A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho -substituted anilines bearing N, N -, N, O -, and N, S -bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free.
Iodide catalyzed synthesis of 2-aminobenzoxazoles via oxidative cyclodesulfurization of phenolic thioureas with hydrogen peroxide
Yadav, Vinod K.,Srivastava, Vishnu P.,Yadav, Lal Dhar S.
, p. 252 - 255 (2017/12/26)
A convenient and efficient oxidative cyclodesulfurization of o-phenolic thioureas to 2-aminobenzoxazoles employing TBAI (tetrabutylammonium iodide)/H2O2 catalyst/reagent system is reported. The protocol utilizes and offers a number o
One-pot reaction for the synthesis of N-substituted 2-aminobenzoxazoles using triphenylbismuth dichloride as cyclodesulfurization reagent
Murata, Yuki,Matsumoto, Natsuho,Miyata, Maya,Kitamura, Yuki,Kakusawa, Naoki,Matsumura, Mio,Yasuike, Shuji
, p. 18 - 23 (2018/02/09)
The treatment of various 2-aminophenols with isothiocyanates afforded thioureas, which were reacted in situ with triphenylbismuth dichloride in the presence of triethylamine to give the expected N-substituted benzoxazol-2-amines in good to excellent yields. Triphenylbismuth dichloride promoted the successful cyclodesulfurization of thioureas with short reaction times under mild reaction conditions. This reaction is the first example of the synthesis of heterocyclic rings using a pentavalent organobismuth reagent.
Ultrasound-assisted synthesis of substituted 2-aminobenzimidazoles, 2-aminobenzoxazoles, and related heterocycles
Phakhodee, Wong,Duangkamol, Chuthamat,Wiriya, Nittaya,Pattarawarapan, Mookda
supporting information, p. 5290 - 5293 (2016/11/11)
A sonochemical method for the synthesis of 2-aminobenzimidazoles and 2-aminobenzoxazoles, as well as chiral aminooxazolines and a chiral substituted quinazolin-5-one is reported. Using the Ph3P–I2system in the presence of triethylami
Highly efficient one-pot synthesis of 2-aminobenzoxazoles using triflic acid as a cyclodesulfurizing reagent
Khatik, Gopal L.,Dube, Namita,Pal, Anang,Nair, Vipin A.
experimental part, p. 2631 - 2639 (2011/08/07)
An efficient one-pot synthetic strategy for 2-aminobenzoxazoles was developed from isothiocyanates and 2-aminophenol using triflic acid as a cyclodesulfurizing reagent. Taylor & Francis Group, LLC.
One-pot synthesis of five and six membered N, O, S-heterocycles using a ditribromide reagent
Yella, Ramesh,Patel, Bhisma K.
experimental part, p. 754 - 763 (2010/11/03)
In a one-pot procedure, bromine less brominating reagent 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been utilized as an efficient desulfurizing agent for the construction of a library of heterocycles containing N, O, and S starting from aryl/alkyl isothiocyanates. In this approach, aryl/alkyl isothiocyanate reacts with o-phenylenediamine (o-PD), o-aminophenol, and o-aminothiophenol to form their monothiourea which on desulfurization with EDPBT led to the formation of corresponding 2-aminobenzimidazoles, 2-aminobenzoxazoles, and 2-aminobenzothiazoles, respectively. An interesting regioselectivity was observed for unsymmetrical thiourea having a naphthyl moiety on the one side and an ortho amino or an ortho hydroxy phenyl group on the other side giving a completely different product which is mainly dependent on the nature of the nucleophiles (-OH or -NH 2). Further, the bis-thioureas resulted from the aliphatic 1,2-diamine with 2 equiv of aryl isothiocyanates on treatment with EDPBT gave imidazolidenecarbothioamides, whereas bis-thioureas resulted from aromatic 1,2-diamine yielded benzimidazoles with concurrent expulsion of an isothiocyanate unit. This method is simple and applied to various substrates which are amenable to bromination that reveals the desulfurizing ability of EDPBT predominating over its brominating ability. Finally, the spent reagent EDPDB can be recovered, regenerated, and reused without any loss of activity.
Synthesis and evaluation of benzoxazole derivatives as 5-lipoxygenase inhibitors
Song, Hyunmin,Oh, Sei-Ryang,Lee, Hyeong-Kyu,Han, Gyoonhee,Kim, Joo-Heon,Chang, Hyeun Wook,Doh, Kyung-Eun,Rhee, Hee-Kyung,Choo, Hea-Young Park
experimental part, p. 7580 - 7585 (2011/01/04)
5-Lipoxygenase (5-LOX) is important enzyme in the biosynthesis of leukotrienes, and is a potential target in the treatment of asthma and allergy. We designed and synthesized a series of benzoxazoles and benzothiazoles as 5-LOX inhibitors. Fourteen compoun
