- Solid Supported Nano Structured Cu-Catalyst for Solvent/Ligand Free C2 Amination of Azoles
-
Ligand- and solvent-free catalytic conditions that harness a nanostructured–CuI catalyst encapsulated in TiO2 has been reported for C2-amination of azoles (benzothiazole, benzoxazole and thiazole). The reaction is highly regioselective. The catalyst is robust, inexpensive and can be recycled up to four times. This strategy was further used for the synthesis of a small molecule with anti-HIV and anti-tumor properties.
- Dutta, Pratip Kumar,Sen, Subhabrata,Saha, Debasree,Dhar, Basabbijayi
-
-
Read Online
- Direct amination of azoles using CuCl2 complexes of amines under mild conditions
-
The efficient direct amination of azoles, including benzoxazole, benzothiazole and 1-methylbenzimidazole, was accomplished in moderate to good yields using CuCl2 complexes of amines as a readily available and effective nitrogen source. The coupling reactions were performed under mild conditions: at 30-50°C within 3-6 h, in air without oxidant, additive, ligand and anhydrous conditions.
- Xu, Juan,Li, Jiarong,Wei, Zhen,Zhang, Qi,Shi, Daxin
-
-
Read Online
- Free Radical Synthetic Protocol for Benzothiazoles via Ring Opening of Benzotriazole: A Two-step Organic Chemistry Experiment for Undergraduate and Postgraduate Students
-
The utility and advantages of benzotriazole methodology have been described for the practical synthesis of benzothiazoles. The two-step synthetic procedure includes nucleophilic acyl substitution followed by benzotriazole ring cleavage under the free radical condition and subsequent cyclization via elimination of molecular nitrogen (N2). This protocol requires cheap and readily available reagents, and moreover easy to handle, thus can be used to teach undergraduate and postgraduate students about the importance of benzotriazole moiety in organic synthesis, ring cleavage chemistry, cyclization reactions, and use of industrial waste in free radical reactions. Students can also learn some important and common techniques useful in organic chemistry such as monitoring of organic reaction using thin-layer chromatography and UV, microwave (MW) technique for the synthesis, and column chromatography for the product isolation and structure determination through NMR, MS, and IR spectral analysis of the pure compounds.
- Singh, Anoop S.,Mishra, Nidhi,Yadav, Mangal S.,Tiwari, Vinod K.
-
-
Read Online
- Room-temperature nickel-catalyzed amination of heteroaryl/aryl chlorides with Ni(II)-(σ-Aryl) complex as precatalyst
-
The room-temperature cross-coupling of heteroaryl and aryl chlorides with secondary cyclic amines can be effected using Ni(II)-(σ-aryl) complex as pre-catalyst. Some useful aromatic and heteroaromatic amine derivatives were readily synthesized in moderate to good yields in the presence of the Ni(II)-(σ-aryl) complex/NHC/KOtBu/toluene system.
- Fan, Xin-Heng,Li, Gang,Yang, Lian-Ming
-
-
Read Online
- Ionic Reactivity of 2-Isocyanoaryl Thioethers: Access to 2-Halo and 2-Aminobenzothia/Selenazoles
-
An ionic cascade insertion/cyclization reaction of thia-/selena-functionalized arylisocyanides has been successfully developed for the efficient and practical synthesis of 2-halobenzothiazole/benzoselenazole derivatives. This synthetic protocol, incorporating a halogen atom when forming the five-membered ring of benzothia/selenazoles, is different from the existing ones, where halogenation of the preformed benzothia/selenazole precursors happens. Additionally, a facile access to 2-aminobenzothiazoles is also achieved by the one-pot cascade reaction of 2-isocyanoaryl thioethers, iodine, and amines.
- Dong, Jinhuan,Hu, Junlin,Liu, Xiaoli,Sun, Shaoguang,Bao, Lan,Jia, Mengying,Xu, Xianxiu
-
p. 2845 - 2852
(2022/02/23)
-
- Copper(ii) ions supported on functionalized graphene oxide: an organometallic nanocatalyst for oxidative amination of azolesviaC-H/C-N bond activation
-
Graphene oxide (GO) was chemically modified withpara-aminobenzoic acid (PABA) to immobilize copper(ii) ions on its surface and used as a nanocatalyst for the oxidative C(sp2)-H bond amination reaction. A practical method to prepare Cu2+supported onpara-aminobenzoic acid grafted on GO was reported. The prepared Cu2+@GO/PABA was characterized by FT-IR, XRD, SEM, AFM, TEM, UV-Vis, and ICP techniques. The results showed that the morphology, distribution, and loading of copper ions could be well-adjusted by grafting of PABA on GO. Moreover, just 2 mol% of Cu2+@GO-PABA could catalyze the C-H activation reaction of benzoxazole and benzothiazole with secondary amines in >94% yields. Also, the catalyst showed very good recyclability and much less leaching of the Cu into the reaction solution. The high activity of Cu2+@GO-PABA can be ascribed to the good synergistic effects of Cu2+andpara-aminobenzoic acid grafted on graphene oxide.
- Behzadi, Masoumeh,Mahmoodi Hashemi, Mohammad,Roknizadeh, Mostafa,Nasiri, Shahrokh,Ramazani Saadatabadi, Ahmad
-
supporting information
p. 3242 - 3251
(2021/02/26)
-
- Room-Temperature Amination of Chloroheteroarenes in Water by a Recyclable Copper(II)-Phosphaadamantanium Sulfonate System
-
Buchwald-Hartwig amination of chloroheteroarenes has been a challenging synthetic process, with very few protocols promoting this important transformation at ambient temperature. The current report discusses about an efficient copper-based catalytic system (Cu/PTABS) for the amination of chloroheteroarenes at ambient temperature in water as the sole reaction solvent, a combination that is first to be reported. A wide variety of chloroheteroarenes could be coupled efficiently with primary and secondary amines as well as selected amino acid esters under mild reaction conditions. Catalytic efficiency of the developed protocol also promotes late-stage functionalization of active pharmaceutical ingredients (APIs) such as antibiotics (floxacins) and anticancer drugs. The catalytic system also performs efficiently at a very low concentration of 0.0001 mol % (TON = 980,000) and can be recycled 12 times without any appreciable loss in activity. Theoretical calculations reveal that the π-acceptor ability of the ligand PTABS is the main reason for the appreciably high reactivity of the catalytic system. Preliminary characterization of the catalytic species in the reaction was carried out using UV-VIS and ESR spectroscopy, providing evidence for the Cu(II) oxidation state.
- Dandela, Rambabu,Desai, Aman A.,Kapdi, Anant R.,Kori, Santosh,Maity, Dilip K.,Parmar, Udaysinh,Somvanshi, Dipesh
-
p. 8900 - 8925
(2021/07/20)
-
- Nickel-Catalyzed Amination of (Hetero)aryl Halides Facilitated by a Catalytic Pyridinium Additive
-
An efficient and operationally simple Ni-catalyzed amination protocol has been developed. This methodology features a simple NiII salt, an organic base and catalytic amounts of both a pyridinium additive and Zn metal. A diverse number of (hetero)aryl halides were coupled successfully with primary and secondary alkyl amines, and anilines in good to excellent yields. Similarly, benzophenone imine gave the corresponding N-arylation product in an excellent yield.
- Han, Dongyang,Li, Sasa,Xia, Siqi,Su, Mincong,Jin, Jian
-
supporting information
p. 12349 - 12354
(2020/09/09)
-
- Dioxygen-triggered oxidative cleavage of the C-S bond towards C-N bond formation
-
Research on the cleavage of C-C bonds has been well developed. By comparison with this, the activation of C-S bonds remains challenging. Herein, dioxygen-triggered oxidative cleavage of C-S bonds has been achieved, delivering a series of N-containing heterocyclic compounds that are frequently found in pesticides and pharmaceuticals. Additionally, the potential utility of this protocol was further demonstrated by a gram-scale experiment. Mechanistically, dioxygen plays a key role in the cleavage of C-S bonds towards C-N bond formation.
- Lv, Zongchao,Wang, Huamin,Quan, Zhicong,Gao, Yuan,Lei, Aiwen
-
supporting information
p. 12332 - 12335
(2019/10/19)
-
- HFIP Promoted Low-Temperature SNAr of Chloroheteroarenes Using Thiols and Amines
-
A highly efficient and an unprecedented hexafluoro-2-propanol, promoting low-temperature aromatic nucleophilic substitutions of chloroheteroarenes, has been performed using thiols and (secondary) amines under base-free and metal-free conditions. The developed protocol also provides excellent regio-control for the selective functionalization of dichloroheteroarenes, while the utility of the protocol was demonstrated by the modification of a commercially available drug ceritinib.
- Bhujabal, Yuvraj B.,Vadagaonkar, Kamlesh S.,Gholap, Aniket,Sanghvi, Yogesh S.,Dandela, Rambabu,Kapdi, Anant R.
-
p. 15343 - 15354
(2019/12/04)
-
- Electrochemical intramolecular dehydrogenative C-S bond formation for the synthesis of benzothiazoles
-
An external oxidant-free intramolecular dehydrogenative C-S cross-coupling has been developed under undivided electrolytic conditions. Various 2-aminobenzothiazoles could be synthesized with up to 99% yield from the direct combination of aryl isothiocyanates with amines. In the presence of a base, this reaction protocol is also applicable for the synthesis of benzothiazoles from N-aryl thioamides.
- Wang, Pan,Tang, Shan,Lei, Aiwen
-
supporting information
p. 2092 - 2095
(2017/07/24)
-
- Metal-Free Synthesis of 2-Aminobenzothiazoles via Iodine-Catalyzed and Oxygen-Promoted Cascade Reactions of Isothiocyanatobenzenes with Amines
-
In this paper, a highly efficient and sustainable synthesis of 2-aminobenzothiazoles through the cascade reactions of isothiocyanatobenzenes with primary or secondary amines by using iodine as a catalyst and oxygen as an oxidant is presented. Mechanistically, the formation of the title compounds involves the in situ formation of the required benzothiourea intermediate followed by its intramolecular cross dehydrogenative coupling of a C(sp2)-H bond and a S-H bond. To our knowledge, this should be the first example in which 2-aminobenzothiazoles are efficiently prepared from simple and cheap isothiocyanates and amines under metal-free conditions by using iodine as a catalyst and molecular oxygen as an oxidant with water as the byproduct. Compared with literature protocols, this method eliminates the use of ortho-halo-substituted precursors, expensive transition-metal catalysts, and hazardous oxidants.
- Xu, Yuanshuang,Li, Bin,Zhang, Xinying,Fan, Xuesen
-
p. 9637 - 9646
(2017/09/23)
-
- A benzothiazole - nitrogen-containing heterocyclic hybrid synthetic method (by machine translation)
-
The invention discloses a through the isothiocyanic benzoate compounds and nitrogen-containing heterocyclic compound of the reaction in series between the benzothiazole - nitrogen-containing heterocyclic hybrid synthetic method. The isothiocyanate benzoate compounds, nitrogen-containing heterocyclic compound, catalyst iodine and solvent are mixed, in the oxygen or air atmosphere, heating to 100 - 140 °C reaction to obtain the benzothiazole - nitrogen-containing heterocyclic hybrid. The synthesis method has the raw materials are simple and easy, simple operation, mild condition, substrate and wide range of application and the like, and has potential industrial application prospect. (by machine translation)
- -
-
Paragraph 0053; 0054; 0055
(2017/11/18)
-
- Metal free amination of 2-chloroazoles in aqueous medium
-
A green approach for the synthesis of 2-amino azoles by the reaction of 2-chloro azoles with various types of amines using water as an environment friendly solvent at room temperature has been developed. The significant features of this methodology are short reaction time and easy product separation. This approach provides various biologically active compounds in good to excellent yields without adding any catalyst, ligand, or base.
- Uday Kumar,Reddy, K. Harsha Vardhan,Anil Kumar,Satish,Reddy, V. Prakash,Nageswar
-
supporting information
p. 637 - 640
(2016/01/26)
-
- Copper-catalyzed synthesis of 2-aminobenzothiazoles from 2-iodophenyl isocyanides, potassium sulfide and amines
-
A simple and practically useful synthetic method for the synthesis of a variety of 2-aminobenzothiazoles was developed. This methodology could construct one C-N bond and two C-S bonds in a step reaction and provide the desired products in good to perfect yields.
- Min, Hao,Xiao, Genhua,Liu, Wenjuan,Liang, Yun
-
p. 11088 - 11091
(2016/12/09)
-
- Palladium-catalyzed amination of aryl sulfides with aliphatic amines
-
Conditions for the palladium-NHC-catalyzed amination of aryl sulfides with aliphatic as well as aromatic amines were established. The KHMDS-mediated amination of heteroaryl sulfides could proceed without palladium. Based on the distinct difference in reactivity of C-Br and C-S bonds, a sequential amination of bromothioanisole can take place to install two different alkylamino groups onto the aromatic ring in one pot. A palladium-NHC precatalyst shows high efficiency for C-S bond cleavage for the amination of aryl sulfides with aliphatic amines or aromatic amines.
- Gao, Ke,Yorimitsu, Hideki,Osuka, Atsuhiro
-
supporting information
p. 2678 - 2682
(2015/04/27)
-
- Ru/C: A simple heterogeneous catalyst for the amination of azoles under ligand free conditions
-
A ligand free Ru/C-catalyzed amination of 2-halo azoles with a broad scope of aminating reagents has been developed. A variety of 2-aminoazole derivatives were synthesized in moderate to good yields by utilizing this protocol. The methodology is operationally simple and not sensitive to air and moisture. It provides potentially useful products by using an inexpensive and recyclable catalytic system under ligand free conditions without significant loss of its catalytic activity up to four cycles. This journal is
- Harsha Vardhan Reddy,Anil Kumar,Prakash Reddy,Uday Kumar,Nageswar
-
p. 45579 - 45584
(2014/12/11)
-
- Arylation of amines and monoarylation of symmetrical diamines in the presence of brine solution with diheteroaryl halides
-
A simple, scalable, ligand-free, and metal-free protocol for arylation of amines and monoarylation of symmetrical diamines with diheteroaryl halides in the presence of brine solution has been developed. The protocol has broad structural applicability for chemoselective monoarylation of a wide variety of symmetrical, cyclic, and acyclic aliphatic diamines. The protocol is also applicable for selective arylation of aliphatic amine in the presence of aromatic amine.
- Verma, Sanjeev K.,Ghorpade, Ramarao,Kaushik
-
supporting information
p. 2645 - 2655
(2014/08/18)
-
- A ligand free copper(II) catalyst is as effective as a ligand assisted Pd(II) catalyst towards intramolecular C-S bond formation via C-H functionalization
-
Copper(I) catalysts are usually ineffective on the other hand Pd(II) catalysts are quite effective in promoting intramolecular sp2 C-H functionalization (C-S bond formation). Herein, we have developed a ligand assisted Pd(II) catalyzed C-S bond formation via C-H activation from arylthioureas leading to the formation of 2-aminobenzothiazoles for substrates bearing electron donating (EDG) groups in the aryl ring. However without the assistance of ligand this Pd(II) catalyzed reaction is quite unproductive particularly for thioureas possessing strongly electron donating groups in the aryl rings. Interestingly, the ligand free Cu(II) catalyzed oxidative cyclization of arylthioureas are equally effective both for arylthioureas possessing electron donating as well as electron withdrawing groups in the aryl rings.
- Banerjee, Arghya,Santra, Sourav Kumar,Rout, Saroj Kumar,Patel, Bhisma K.
-
p. 9096 - 9104
(2013/09/24)
-
- A DBU-diheteroaryl halide adduct as the fastest current N-diheteroarylating agent
-
An unexpected diazabicyclo[5.4.0]undec-7-ene (DBU) catalysed rate enhancement of N-arylation of amines with diheteroaryl halides is reported. DBU is found to activate the Ar-Cl bond of a diheteroaryl halide, forming a green coloured adduct under neat conditions. The activated green coloured adduct was used for the arylation of amines under neat conditions and was found to be the fastest diheteroarylating agent reported to date. The Royal Society of Chemistry 2013.
- Verma, Sanjeev K.,Acharya,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
-
p. 18783 - 18786
(2013/10/22)
-
- An "on-water" exploration of CuO nanoparticle catalysed synthesis of 2-aminobenzothiazoles
-
An "on-water" one-pot process has been engineered for the preparation of 2-aminobenzothiazole from ortho-halo (-F, -Cl, -Br and -I) substituted unsymmetrical thioureas. For ortho -I and -Br substrates the reactions afford 2-aminobenzothiazoles under metal free condition promoted by base. However, the relatively inert ortho -Cl and -F substrates undergo intramolecular arylthiolation only in the presence of CuO nanoparticles yielding 2-aminobenzothiazoles. This methodology provides easy access to aminobenzothiazoles utilising even the ortho -Cl and -F substrates. The catalyst is recyclable several times without loss of substantial activity. Other remarkable features include the wide range of functional group tolerance, absence of chromatographic purification (for ortho -I and -Br substrates) and providing moderate to excellent yield of the products under mild conditions, thus rendering the methodology as a highly eco-friendly alternative to the existing methods.
- Rout, Saroj Kumar,Guin, Srimanta,Nath, Jayashree,Patel, Bhisma K.
-
p. 2491 - 2498
(2013/02/21)
-
- Chemospecific and ligand free CuI catalysed heterogeneous N-arylation of amines with diheteroaryl halides at room temperature
-
A ligand free, copper-catalyzed N-arylation reaction of amines with diheteroaryl halides in heterogeneous medium at room temperature has been developed. The protocol is very effective for low boiling amines and useful for amines available in aqueous solution. The reaction gives chemospecific arylation of amines with diheteroaryl halides in the mixture monoheteroaryl halides, diheteroaryl halides and carbocyclic aryl halides. The reaction is also chemospecific with respect to arylation of aliphatic amines. Monoarylated piperazines were also synthesized at room temperature following this protocol. The Royal Society of Chemistry 2011.
- Verma, Sanjeev K.,Acharya,Kaushik
-
supporting information; experimental part
p. 1324 - 1327
(2011/04/16)
-
- Arylthioureas with bromine or its equivalents gives no 'Hugerschoff' reaction product
-
The in situ generated aryl-alkyl unsymmetrical thiourea obtained by the reaction of an aryl isothiocyanate with an aliphatic secondary amine on treatment with bromine or its equivalent gave exclusively a product having a thioamido guanidino moiety and not the expected Hugerschoff product 2-aminobenzothiazole. A plausible reaction mechanism has been proposed for this unprecedented transformation and the scope has been extended to various substrates. The Royal Society of Chemistry 2010.
- Yella, Ramesh,Murru, Siva,Ali, Abdur Rezzak,Patel, Bhisma K.
-
experimental part
p. 3389 - 3393
(2010/08/22)
-
- Metal-free synthesis of 2-substituted (N, O, C) Benzothiazoles via an intramolecular C-S bond formation
-
An efficient, economical, and convenient method was developed for the preparation of 2-substituted (N, O, C) benzothiazoles from N′-substituted- N-(2-halophenyl)thioureas, O′-substituted-N-(2-halophenyl) carbamothioates, or N-(2-halophenyl) thioamides via a base-promoted cyclization in dioxane without any transition metal. A one-pot variant combining the synthesis of the thiourea and the cyclization was also demonstrated. High yields were obtained, and a variety of functional groups were tolerated under these conditions. Transition-metal-free, mild reactive conditions, wide application scope, and shorter reaction times make this method superior to the reported methods for the synthesis of 2-substituted benzothiazoles and suitable for combinatorial format.
- Feng, Enguang,Huang, He,Zhou, Yu,Ye, Deju,Jiang, Hualiang,Liu, Hong
-
experimental part
p. 422 - 429
(2010/09/05)
-
- The reaction of benzothiazolyl substituted α-phosphorylmethyl sulfoxides with several amines
-
We have examined the reactivities of α-phosphorylmethyl benzothiazolyl sulfoxides in the thermolyses and in the presence of several amines, such as aniline, benzylamine, piperidine, morpholine, and pyrrolidine. Thermolyses of the derivatives in the presen
- Morita, Hiroyuki,Tashiro, Shintaro,Takeda, Masahiro,Yamada, Nobuhiko,Sheikh, Md. Chanmiya,Kawaguchi, Hiroyuki
-
p. 4496 - 4505
(2008/09/20)
-
- Chloroformamidinium salts: Efficient reagents for preparation of 2-aminobenzoimidazole, 2-aminobenzoxazole, and 2-aminobenzothiazole derivatives
-
A Reaction involving chloroformamidinium salts (TCFH 1a, BTCFH 1b, DmCFH 1c, DmPCFH 1d, BPCFH 1e) and 2-aminophenol 9a, benzene-1,2-diamine 9b, and 2-aminothiophenol 9c afforded 2-aminobenzoxazole 13, 2-aminobenzoimidazole 14, and 2-aminobenzothiazole 15 derivatives, respectively as major products, due to the in situ heterocyclization with dimethylamine acting as the better leaving group. Attempts for preparation of 13-15 from the reaction of N,N-dimethyl carbomyl chloride 16 with 2-aminophenol 9a, benzene-1,2-diamine 9b, and 2-aminothiophenol 9c were unsuccessful, and gave the unexpected products benzoxazol-2-ol 18a, benzoimidazol-2-one 18b, and S-(2-amino-phenyl) N,N-dimethylthiocarbamate 19 respectively. On the other hand reaction of chloroformamidinium salts 1a-e with 3-benzyl-2-hydrazinoquinoxaline 3 and 1-hydrazinophthalazine hydrochloride 4 in the presence of triethylamine as a base, afforded the [1,2,4]triazolo derivatives 6 and 7 respectively in good yield and purity. These triazole derivatives were formed due to the strong tendency towards heterocyclization and substitution of dimethylamine group as a better leaving group.
- El-Faham, Ayman,Chebbo, Mohamed,Abdul-Ghani, Mohamed,Younes, Ghassan
-
p. 599 - 606
(2007/10/03)
-
- One-pot synthesis of 2-aminobenzothiazoles using a new reagent of [Bmim]Br3 in [Bmim]BF4
-
The one-pot direct synthesis of 2-aminobenzothiazoles from phenyl isothiocyanate and amines using a new reagent of 1-butyl-3-methylimidazolium tribromide ([Bmim]Br3) in ionic liquid 1-butyl-3-methyl-imidazolium tetraflouoroborate ([Bmim]BF4) is described.
- Le, Zhang-Gao,Xu, Jian-Ping,Rao, Huo-Yu,Ying, Min
-
p. 1123 - 1124
(2007/10/03)
-
- Unexpected dealkylation during nucleophilic substitution: Synthesis of 2-N,N-dialkylamino benzoxazoles and benzothiazoles
-
Mild reaction conditions are described for the preparation of a number of 2-alkyl- and 2-arylaminobenzoxazoles and benzothiazoles from 2-chlorobenzoxazole and 2-chlorobenzothiazole and N-methyl or other simple N-alkyl tertiary amines. The reaction proceeds neat or in THF solution and involves dealkylation of the amine reactant by nucleophilic substitution by chloride. In the case of N-methylpyrrolidine and N-methylpiperidine demethylation was not observed and the major product was formed by ring opening to give chlorobutyl- and chloropentyl-methylamino substituted benzoxazoles and benzothiazoles. Treatment of the chlorobutyl derivative with iodide in acetone afforded the new 1H,2H,3H,4H,5H-[1,3]diazepino[2,1-b][1,3]benzoxazol-6-ium ring system. (C) 2000 Elsevier Science Ltd.
- Khalaf, Abedawn I,Alvarez, Ricardo G,Suckling, Colin J,Waigh, Roger D
-
p. 8567 - 8571
(2007/10/03)
-
- Non-imidazole histamine H3 ligands, part 2: New 2-substituted benzothiazoles as histamine H3 antagonists
-
New, non-imidazole histamine H3 receptor antagonists were prepared and in vitro tested as H3 receptor antagonists measured as the electrically evoked contraction of the guinea-pig jejunum. The 2-(1-piperidinyl)- and 2- (1-pyrrolidinyl)benzothiazoles show no or very poor activity; 2-[1-(4- amino)piperidinyl]- and 2-(1,2-ethanediamino)- and (2-(1,3- propanediamino)derivatives of benzothiazole possess weak activity at H3 receptors, whereas 2-(4-piperidinyl)benzothiazoles and 2-[1-(4- piperazinyl)]benzothiazoles show moderate to good activity. Lipophilic and not-too-bulky substituents like n-propyl attached to the nitrogen at the piperazine or piperidine ring lead to potent H3 receptor antagonists with pA2 values ranging from 7.0 to 7.2. The structure-activity relationships for different substitution patterns are discussed.
- Walczynski, Krzysztof,Guryn, Roman,Zuiderveld, Obbe P.,Timmerman, Henk
-
p. 389 - 398
(2007/10/03)
-
- Acyclic Tertiary Amines as Nucleophiles in Substitution Reactions of Aromatic and Heteroaromatic Halides
-
Even acyclic tertiary amines such as triethylamine, tri-n-propylamine and tri-n-butylamine, which have been believed to be inert to aromatic and heteroaromatic halides, underwent SNAr reactions with aromatic and heteroaromatic halides to give the dialkylamino derivatives; in the case of monocyclic amines like N-methylpyrrolidine and N-methylpiperidine, the dealkylation being regioselective.
- Matsumoto, Kiyoshi,Hashimoto, Shiro,Otani, Shinichi
-
p. 306 - 307
(2007/10/02)
-
- ETUDE DE LA FRAGMENTATION PAR IMPACT ELECTRONIQUE DE DERIVES DU BENZOTHIAZOLE
-
The mass spectra of eighteen substituted benzothiazoles are reported and discussed.All these compounds are thermodynamically stable and give an intense molecular ion, which undergoes different types of fragmentation depending on the nature of the substituent which is rarely eliminated directly. β-Cleavage with respect to the heterocyclic double bond is often obseved.Specific 2H-, 13C-, 15N- and 34S-labelling have been used in order to confirm the fragmentation patterns.
- Claude, Saturnin,Tabacchi, Raffaele,Duc, Laurent,Fuchs, Rudolf,Boosen, Karl-Josef
-
p. 682 - 692
(2007/10/02)
-