- Preparation method of thiourea alkylation derivative
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The invention discloses a preparation method of a thiourea alkylation derivative, which comprises the following steps: stirring an aldehyde, N-arylthiourea, trichlorosilane and Lewis base in an organic solvent at a range of -10 DEG C to room temperature for reaction, and carrying out after-treatment to obtain the thiourea alkylation derivative, wherein the molar ratio of the aldehyde to the N-arylthiourea is 1:2 to 2:1, the molar ratio of the aldehyde to the Lewis base is 1:(0.01-0.20), the molar ratio of the aldehyde to trichlorosilane is 1:(1-2), R1 is a C1-C5 saturated alkyl group, or an unsubstituted or substituted aromatic ring, and R2 is H, an electron withdrawing substituent or an electron donating substituent. According to the method, trichlorosilane is catalyzed by the micromolecular Lewis base, reductive alkylation of thiourea is realized, synthesis can be realized by a one-pot method, and the method is simple to operate, short in reaction time, low in substrate toxicity, lowin cost, easy to obtain, mild in reaction condition and high in safety.
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Paragraph 0037-0044; 0058-0062
(2021/03/31)
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- Facile synthesis of phthalidyl fused spiro thiohydantoins through silica sulfuric acid induced oxidative rearrangement of ninhydrin adducts of thioureas
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A one-pot three-component sequential synthetic protocol produces structurally and biologically important phthalidyl fused spiro N,N′-disubstituted thiohydantoins from readily available aromatic isothiocyanates, primary amines and ninhydrin. In this three-step synthesis while the initial two steps are catalyst-free, in the final step silica sulfuric acid (SSA) induces an oxidative rearrangement in [3.3.0]-bicyclic 1,2-diol adducts of ninhydrin and thioureas under solvent-free condition to generate the final products spiro-fused thiohydantoins. The adequate acidity of SSA in cooperation with moderate oxidizing property promotes a facile oxidative rearrangement in 1,2-diol intermediates to produce the spiro-fused thiohydantoins with diverse functionalities. Easy recyclability of SSA, good to excellent yield of the products, wider substrate scope, shorter reaction time, solvent-free two steps out of three and high atom economy make this method attractive and practicable.
- Mandal, Subhro,Pramanik, Animesh
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- An isocyanide based multi-component reaction under catalyst- and solvent-free conditions for the synthesis of unsymmetrical thioureas
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A new and efficient method for the synthesis of thiourea derivatives by a sequential one-pot, three-component reaction between aromatic isocyanides, amines, and 1,2-di-tert-butyldisulfane (DTBS) was developed and 27 different examples were synthesized in good to excellent yields. DTBS was identified as an effective sulfur surrogate without the use of both catalysts and solvents. This protocol does not employ any transition metal catalyst or special experimental setup.
- Singh, Karandeep,Sharma, Siddharth
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p. 197 - 201
(2016/12/28)
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- NEW FLUOROUS TAGGING AND SCAVENGING REACTANTS AND METHODS OF SYNTHESIS AND USE THEREOF
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The present invention includes methods and compositions for increasing the fluorous nature of an organic compound by reacting it with at least one fluorous compound to produce a fluorous tagged organic compound. The increased fluorous nature of the fluorous tagged organic compound can then be utilized to separate the fluorous organic compound from untagged reagents, reactants, catalysts and/or products derived therefrom. The resultant fluorous tagged organic compound can be subjected to subsequent chemical transformations, wherein the fluorous nature of the tagged compound is utilized to increase the ease of separation of the fluorous tagged organic compound from untagged reagents, reactants, catalysts and/or products derived therefrom, after each chemical transformation. The chemical transformations result in a second fluorous tagged organic compound wherein the fluorous nature of the second fluorous tagged organic compound can then be reduced by removing the fluorous group therefrom, thereby producing a second organic compound that may be employed as a pharmaceutical compound or intermediate, or a combinatorial library component.
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Page 58, 59, 61
(2008/06/13)
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- Fluorous electrophilic scavengers for solution-phase parallel synthesis
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A fluorous isatoic anhydride and isocyanate are synthesized and used as scavengers for amines in solution-phase parallel synthesis of urea, thiourea, and β-hydroxyamine analogs. The resulting fluorous derivatives are readily separated from the reaction mi
- Zhang, Wei,Chen, Christine Hiu-Tung,Nagashima, Tadamichi
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p. 2065 - 2068
(2007/10/03)
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