- Method for preparing N, N '-diisopropylthiourea
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The invention discloses a method for preparing N, N '-diisopropylthiourea, which relates to the technical field of organic chemical synthesis, and comprises the following steps: adding isopropylamineinto a reactor, controlling the temperature at 50-60 DEG C by using xylene as a solvent, and dropwisely adding carbon disulfide to react; after dropwise adding is finished, raising the temperature andkeeping the temperature for 1-2h for desulfurization, and reacting to generate hydrogen sulfide and N, N '-diisopropylthiourea; absorbing hydrogen sulfide with liquid caustic soda, cooling the N, N '-diisopropylthiourea solution, carrying out suction filtration, and drying to obtain the product. The method is simple in process, high in reaction selectivity and low in risk; meanwhile, tail gas iseasy to treat, generated sulfur can be absorbed by liquid caustic soda in an absorption tank, products can be sold out, and the tail waste treatment problem is solved; after the process is optimized,the yield of N, N '-diisopropylthiourea is increased to 99.55% or above, the purity reaches 99.90% or above, and the melting point is 145-147 DEG C.
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Paragraph 0017-0021
(2021/01/20)
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- Process method for increasing yield of N, N '-diisopropylcarbodiimide product
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The invention discloses a process method for improving the yield of an N, N '-diisopropylcarbodiimide product, and relates to the technical field of organic chemical synthesis, and the process methodcomprises the following steps: reacting isopropylamine and carbon disulfide by using chlorobenzene as a solvent to generate diisopropylthiourea, and carrying out suction filtration; using hydrogen peroxide as an oxidizing agent, using ethyl tert-butyl ether as a solvent, performing primary oxidation, removing hydrogen sulfideafter oxidation to generate N, N '-diisopropylcarbodiimide and sulfur; carrying out secondary oxidation, removing sulfur by using sodium hydrosulfide, washing with water, drying, evaporating out the solvent, adding potassium carbonate into the DIC crude product without thesolvent, controlling the temperature to be 55-65 DEG C, stirring for 0.3-1 hour, controlling the pressure to be less than -0.08 MPa, and distilling to obtain qualified DIC; by adding potassium carbonate, the stability of N, N '-diisopropylcarbodiimide is facilitated, and the N, N'-diisopropylcarbodiimide is prevented from being decomposed at a high temperature so that the yield is increased.
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Paragraph 0019-0023
(2021/01/29)
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- N,N'-diisopropyl carbodiimide preparation method
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The invention belongs to the technical field of organic synthesis and particularly relates to an N,N'-diisopropyl carbodiimide preparation method. The method includes steps: adopting isopropylamine and carbon disulfide to synthesize N,N'-diisopropyl thiourea in a solvent; subjecting the N,N'-diisopropyl thiourea to suction filtration, drying and primary oxidization; performing secondary oxidization reaction, adding a catalyst and an oxidant, and performing reaction for 1h at 60-65 DEG C; performing desulfurizing treatment, adding sodium sulfide solution into oxidation liquid, heating to 70-75DEG C, and performing reaction for 1-2h; adding caustic soda flakes to neutralize, washing, separating a water layer, adding a drying agent for drying, evaporating out the solvent, and performing vacuum rectification to obtain N,N'-diisopropyl carbodiimide. The N,N'-diisopropyl carbodiimide preparation method has advantages that wastewater recycling can be realized, emission is avoided, and accordingly environmental pollution is avoided; simplicity in feeding and aftertreatment, low production cost, high yield and high purity are realized.
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Paragraph 0037-0038; 0044; 0050
(2019/04/06)
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- An Environment-friendly Synthesis of 2,3-Disubstituted-2-iminothiazoline-4-ones
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A series of 2,3-substituted-2-iminothiazoline-4-ones derivatives have been synthesized via an improved method including an auto-catalyzed reaction. This method avoided using any extra catalyst except for the reaction material. This method has been successful in both the aromatic substituted 2-iminothiazolines and the alkyl substituted 2-iminothiazolines. The special product with a hydroxyl group on the 2-iminogroup of 1,3-thiazoline-4-ones has also been obtained unexpectedly. The possible mechanism has been proposed for the special process of dealkylation and hydroxylation. This method offered a special way to afford the 2-hydroxyimino-substituted thiazoline-4-one derivatives in an efficient and eco-friendly way. The mechanism of the transformation under acid condition has also been proposed.
- Meng, Ge,Zheng, Meilin,Dong, Mengshu,Wang, Mei,Zheng, Aqun,Guo, Zengjun
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p. 588 - 594
(2016/04/19)
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- Green process development for the synthesis of aliphatic symmetrical N,N'-disubstituted thiourea derivatives in aqueous medium
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A highly efficient green process for the synthesis of N,N'-disubstituted aliphatic thiourea derivatives using primary aliphatic amines and carbon disulfide in aqueous medium at room temperature via a nonisothiocyanate route is described. This protocol illustrates the rapid preparation of N,N'-disubstituted aliphatic thiourea derivatives in excellent yields with some advantages such as no catalyst and simple workup without any side product formation. Moreover the new route is concise, chromatography-free, and adaptable to pilot-scale preparation.
- Jangale, Asha D.,Kumavat, Priyanka P.,Wagh, Yogesh B.,Tayade, Yogesh A.,Mahulikar, Pramod P.,Dalal, Dipak S.
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supporting information
p. 236 - 244
(2015/10/29)
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- Green Process Development for the Synthesis of Aliphatic Symmetrical N,N ′-Disubstituted Thiourea Derivatives in Aqueous Medium
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A highly efficient green process for the synthesis of N,N′-disubstituted aliphatic thiourea derivatives using primary aliphatic amines and carbon disulfide in an aqueous medium at room temperature via a nonisothiocyanate route is described. This protocol illustrates the rapid preparation of N,N′-disubstituted aliphatic thiourea derivatives in excellent yields with some advantages such as no catalyst and simple workup without any side product formation. Moreover, the new route is concise, does not require chromatography, and is adaptable to pilot-scale preparation. GRAPHICAL ABSTRACT.
- Jangale, Asha D.,Kumavat, Priyanka P.,Wagh, Yogesh B.,Tayade, Yogesh A.,Mahulikar, Pramod P.,Dalal, Dipak S.
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supporting information
p. 376 - 385
(2015/10/29)
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- Enhanced anion binding from unusual coordination modes of bis(thiourea) ligands in platinum group metal complexes
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Treatment of a range of bis-(thiourea) ligands with inert organometallic transition-metal ions gives a number of novel complexes that exhibit unusual ligand binding modes and significantly enhanced anion binding ability. The ruthenium(II) complex [Ru(η6-p-cymene)(κS,S′,N-L 3-H)] + (2b) possesses juxtaposed four- and seven-membered chelate rings and binds anions as both 1:1 and 2:1 host guest complexes. The pyridyl bis(thiourea) complex [Ru(η6-p-cymeme)(κS,S′, Npy-L4)]2+ (4) binds anions in both 1:1 and 1:2 species, whereas the free ligand is ineffective because of intramolecular NH...N hydrogen bonding. Novel palladium(II) complexes with nine- and ten-membered chelate rings are also reported.
- Laura Soriano,Lenthall, Joseph T.,Anderson, Kirsty M.,Smith, Stephen J.,Steed, Jonathan W.
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supporting information; experimental part
p. 10818 - 10831
(2010/12/18)
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- A CONVENIENT METHOD FOR THE PREPARATION OF N,N'-DISUBSTITUTED THIOUREAS USING 2-CHLOROPYRIDINIUM SALT, SODIUM TRITHIOCARBONATE AND AMINES
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N,N'-Disubstituted thioureas were prepared in high yields by treating 2-chloropyridinium salt with sodium trithiocarbonate and subsequently adding amines.
- Takikawa, Yuji,Inoue, Noriyuki,Sato, Ryu,Takizawa, Saburo
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p. 641 - 642
(2007/10/02)
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- Cephalosporin displacement reaction
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The present invention is directed to a process for the displacement of the acetoxy group of a cephalosporanic acid by a sulfur nucleophile, in an organic solvent and under essentially anhydrous conditions.
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