- Organophosphine-free copper-catalyzed isothiocyanation of amines with sodium bromodifluoroacetate and sulfur
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A copper-catalyzed isothiocyanation of amines with sodium bromodifluoroacetate and sulfur in the absence of organophosphine has been established. This approach represents a simple and efficient one-pot synthesis of isothiocyanates, and features excellent functional group tolerance and the use of a cheap, safe and odorless sulfur source. Moreover, this process could directly provide isothiocyanate analogous bioactive molecules, thiocarbonyl-containing pesticides and facile construction of benzoxazole and benzimidazole frames.
- Feng, Wei,Zhang, Xing-Guo
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supporting information
p. 1144 - 1147
(2019/01/28)
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- Isothiocyanate synthesized by three components and preparation method of isothiocyanate
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The invention discloses isothiocyanate and a preparation method thereof. The method comprises the steps that primary amine, sodium difluorobromoacetate and elemental sulfur are taken as reactants forreaction; the reaction is carried out under the action of a copper catalyst, wherein the copper catalyst is any one of cuprous chloride, copper bromide, cuprous iodide, copper chloride and copper trifluoromethanesulfonate; an alkali is also added, wherein the alkali is any one of sodium bicarbonate, potassium carbonate, cesium carbonate, potassium phosphate, DABCO and sodium tert-butoxide; the whole reaction is carried out in a solvent, wherein the solvent is acetonitrile or dimethyl sulfoxide, the reaction temperature is 80-120 DEG C, and the reaction time is 10-14 hours. The method can directly synthesize the target product, does not need to separate intermediate products and only needs stirring and heating reaction under normal pressure to obtain the target product, and the yield can beup to 87%; a waste solution is fewer during the reaction, and the method protects the environment and ensures the health of an operator; in addition, a series of isothiocyanate derivatives can be prepared, and the method has a stronger substrate universality.
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Paragraph 0048
(2019/04/26)
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- A novel one-pot synthesis of isothiocyanates and cyanamides from dithiocarbamate salts using environmentally benign reagent tetrapropylammonium tribromide
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A highly efficient and simple protocol for the synthesis of isothiocyanates and cyanamides from their respective amines in the presence of a mild, efficient, and non-toxic reagent tetrapropylammonium tribromide is described. High environmental acceptability of the reagents, cost effectiveness and high yields are the important attributes of this methodology.
- Kuotsu, Neivotsonuo Bernadette,Jamir, Latonglila,Phucho, Tovishe,Sinha, Upasana Bora
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p. 832 - 841
(2018/01/17)
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- Isothiocyanation of amines using the Langlois reagent
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The Langlois reagent was found to be effective for the isothiocyanation of primary amines in the presence of copper iodide and diethyl phosphonate.
- Liao, Yan-Yan,Deng, Jian-Chao,Ke, Yan-Ping,Zhong, Xiao-Lin,Xu, Li,Tang, Ri-Yuan,Zheng, Wenxu
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supporting information
p. 6073 - 6076
(2017/07/10)
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- Synthesis and evaluation of frentizole-based indolyl thiourea analogues as MAO/ABAD inhibitors for Alzheimer's disease treatment
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Alzheimer's disease (AD) is a neurodegenerative disorder associated with an excessive accumulation of amyloid-beta peptide (Aβ). Based on the multifactorial nature of AD, preparation of multi-target-directed ligands presents a viable option to address more pathological events at one time. A novel class of asymmetrical disubstituted indolyl thioureas have been designed and synthesized to interact with monoamine oxidase (MAO) and/or amyloid-binding alcohol dehydrogenase (ABAD). The design combines the features of known MAO inhibitors scaffolds (e.g. rasagiline or ladostigil) and a frentizole moiety with potential to interact with ABAD. Evaluation against MAO identified several compounds that inhibited in the low to moderate micromolar range. The most promising compound (19) inhibited human MAO-A and MAO-B with IC50values of 6.34 μM and 0.30 μM, respectively. ABAD activity evaluation did not show any highly potent compound, but the compound series allowed identification of structural features to assist the future development of ABAD inhibitors. Finally, several of the compounds were found to be potent inhibitors of horseradish peroxidase (HRP), preventing the use of the Amplex Red assay to detect hydrogen peroxide produced by MAO, highlighting the need for serious precautions when using an enzyme-coupled assay.
- Hroch, Lukas,Guest, Patrick,Benek, Ondrej,Soukup, Ondrej,Janockova, Jana,Dolezal, Rafael,Kuca, Kamil,Aitken, Laura,Smith, Terry K.,Gunn-Moore, Frank,Zala, Dominykas,Ramsay, Rona R.,Musilek, Kamil
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p. 1143 - 1152
(2017/02/05)
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- Environmentally benign one-pot synthesis of cyanamides from dithiocarbamates using I2 and H2O2
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An environmentally benign reaction is devised for the synthesis of cyanamides from dithiocarbamate salts using iodine and H2O 2. Taylor & Francis Group, LLC.
- Jamir, Latonglila,Sinha, Upasana Bora,Nath, Jayashree,Patel, Bhisma K.
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experimental part
p. 951 - 958
(2012/02/01)
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- A general and facile one-pot process of isothiocyanates from amines under aqueous conditions
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A general and facile one-pot protocol for the preparation of a broad range of alkyl and aryl isothiocyanates has been developed from their corresponding primary amines under aqueous conditions. This synthetic process involves an in situ generation of a dithiocarbamate salt from the amine substrate by reacting with CS2 followed by elimination to form the isothiocyanate product with cyanuric acid as the desulfurylation reagent. The choice of solvent is of decisive importance for the successful formation of the dithiocarbamate salt particularly for highly electron-deficient substrates. This novel and economical method is suitable for scale-up activities.
- Sun, Nan,Li, Bin,Shao, Jianping,Mo, Weimin,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
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experimental part
p. 61 - 70
(2012/04/04)
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- Efficient preparation of isothiocyanates from dithiocarbamates using bromineless brominating reagent
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For the first time, the crystal structure of a ditribromide reagent 1,1'-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been determined. Utilizing this thiophilic bromineless brominating agent EDPBT, highly useful synthetic intermediates (alkyl and aryl isothiocyanates) have been achieved directly from dithiocarbamates. EDPBT can be easily prepared from readily available reagents. It has been used as a thiophilic reagent, and its thiophilicity dominates over its brominating ability for substrates amenable to bromination. This is a sustainable process for the preparation of isothiocyantes because the spent reagent can be recovered, regenerated, and reused. Copyright Taylor & Francis Group, LLC.
- Yella, Ramesh,Ghosh, Harisadhan,Murru, Siva,Sahoo, Santosh K.,Patel, Bhisma K.
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experimental part
p. 2083 - 2096
(2010/08/19)
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- A one-pot preparation of cyanamide from dithiocarbamate using molecular iodine
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An efficient one-pot method for the synthesis of cyanamides from dithiocarbamate salts via a double desulfurization strategy using molecular iodine is disclosed. Dithiocarbamates, by the action of iodine yield isothiocyanates in situ, which on treatment with aqueous NH3 give thioureas. The thioureas so generated undergo further oxidative desulfurization with I2 giving corresponding cyanamides in good yields. Environmental benignity, cost effectiveness and high yields are the important attributes of this one pot procedure. The Royal Society of Chemistry 2009.
- Nath, Jayashree,Patel, Bhisma K.,Jamir, Latonglila,Sinha, Upasana Bora,Satyanarayana
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experimental part
p. 1503 - 1506
(2010/05/18)
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- 1-phenyl-5-mercapto tetrazoles
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There are disclosed novel compounds which are represented by the formula STR1 wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a 5- or 6-membered heterocyclic moiety, R is H, an alkali metal or a group which is cleavable in aqueous alkaline medium and Z is H, alkyl having from 1 to 10 carbon atoms, aralkyl such as benzyl or phenethyl, phenyl or substituted phenyl. The compounds are useful in photographic applications.
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