- Novel synthesis of S-alkyl thiocarbamates from amines, carbon monoxide, elemental sulfur, and alkyl halides in the presence of a selenium catalyst
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Carbonyl selenide easily reacted with elemental sulfur at low temperature to form carbonyl sulfide in a good yield, and reaction of ammonium salts of selenocarbamates with elemental sulfur brought about ready transformation to those of thiocarbamates. On the basis of the high catalytic activity of selenium for carbonylation of amines with carbon monoxide in addition to these important findings, a convenient new method for synthesis of S-alkyl thiocarbamates was developed through the carbonylation of amines with carbon monoxide and elemental sulfur in the presence of a selenium catalyst under mild conditions followed by alkylation of ammonium salts of the thiocarbamates with alkyl halides.
- Mizuno, Takumi,Nishiguchi, Ikuzo,Sonoda, Noboru
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- Facile S-alkyl thiocarbamate synthesis by a novel DBU-assisted carbonylation of amines with carbon monoxide and sulfur
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A novel DBU-assisted carbonylation of amines with carbon monoxide and sulfur has been developed for the synthesis of S-alkyl thiocarbamates. In the presence of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), S-alkyl thiocarbamates are synthesized in excellent yields from amines, carbon monoxide, sulfur, and alkyl halides under mild conditions (1 atm, 20°C). In the absence of DBU, however, no formation of S-alkyl thiocarbamate is observed. The present DBU-assisted carbonylation can also be applied to new synthetic methods for benthiocarb and orthobencarb (herbicides) and carbamoyl chlorides.
- Mizuno, Takumi,Takahashi, Junko,Ogawa, Akiya
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- A facile, safe and inexpensive preparation of S -methyl arylcarbamothioates by methylthiocarbonylation of primary arylamines with O, S -dimethyl carbonodithioate
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O,S-Dimethyl carbonodithioate is proposed as a suitable and safely handled reagent that can be used in the methylthiocarbonylation of primary arylamines to give S-methyl arylcarbamothioates. Optimal conditions involved a one-step procedure that was carried out at 45C in a solvent-free system, in the presence of triethyl(methyl)ammonium S-methyl carbonodithioate as a reaction promoter. The title products were obtained pure in yields that, with one exception, varied between 72 and 91% (average yield of the 12 considered examples was 83%). The by-product S,S-dimethyl carbonodithioate is also a valuable reagent. Georg Thieme Verlag Stuttgart · New York.
- Degani, Iacopo,Fochi, Rita,Magistris, Claudio
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experimental part
p. 1113 - 1122
(2010/05/19)
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- Metathetic sulfur transfer mediated by N-(2-aminophenyl)-4-methyl-thiazolin-2-thione derivatives: a route to diversely substituted S-alkylcarbamothioates
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A new route to S-alkylcarbamothioates is disclosed. In a first step, N-(2-aminophenyl)-4-methyl-thiazolin-2-thione is transformed into a mono- or disubstituted urea at nitrogen, and then in a second step, alkylated at sulfur. The resulting salts, after treatment with a base, gave S-alkylcarbamothioates in high isolated yields together with 3-methyl[1,3]thiazolo[3,2-a]benzimidazole under very mild conditions.
- Doukara, Abdallah Larbi,Mehdid, Mohammed Amine,Djafri, Ayada,Andreoli, Federico,Vanthuyne, Nicolas,Roussel, Christian
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experimental part
p. 1852 - 1858
(2010/04/04)
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- Solvent-assisted thiocarboxylation of amines and alcohols with carbon monoxide and sulfur under mild conditions
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DMSO or DMF as a solvent strongly accelerated the thiocarboxylation of amines and alcohols with carbon monoxide and sulfur. Under mild conditions (1 atm, 20°C), this thiocarboxylation of amines assisted by DMSO with carbon monoxide and sulfur has been developed into a practical and convenient synthetic method for S-alkyl thiocarbamates in good to excellent yields, including EPTC, thiobencarb, orbencarb, and molinate (herbicides). DMF also showed the similar solvent effect. NMP slightly decreased the effect for the thiocarboxylation of amines, and the yield of S-alkyl thiocarbamate was lowered in DMAc. Surprisingly, no formation of S-alkyl thiocarbamate was observed at the use of the other solvents, such as THF, hexane, toluene, AcOEt, MeCN, MeOH, and H 2O. The present solvent-assisted thiocarboxylation with carbon monoxide and sulfur could be also applied to a new synthesis of S-alkyl O-alkyl carbonothioates from alcohols under mild conditions (1 atm, 20°C) in DMF using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene).
- Mizuno, Takumi,Iwai, Toshiyuki,Ishino, Yoshio
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p. 9157 - 9163
(2007/10/03)
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- A new one-pot synthesis of thiocarbamates from isocyanates and disulfides in the presence of Zn/AlCl3 system
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A novel method has been developed for the synthesis of S-alkyl(aryl) thiocarbamates. The route involves, first, the formation of zinc thiolates by reductive cleavage of disulfides in the presence of Zn/AlCl3 system; then subsequent reaction of
- Movassagh, Barahman,Zakinezhad, Yousef
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p. 1330 - 1331
(2007/10/03)
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- Synthesis of N-aryl S-alkylthiocarbamates
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The synthesis of N-aryl S-alkylthiocarbamates was discussed. The carbamates were synthesized by reactions of isocyanates with LiAlHSH and then with alkyl halides. Melting points were determined by using Yanagimoto micromelting point apparatus and were corrected. It was found that LiAlHSH behaved in a similar fashion as LiAlHSeH.
- Koketsu, Mamoru,Kobayashi, Chikashi,Ishihara, Hideharu
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p. 374 - 378
(2007/10/03)
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