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Thioureas
In organic chemistry, thioureas are members of a family of organosulfur compounds with the formula and structure . The parent member of this class of compounds is thiourea (). Substituted thioureas are found in several commercial chemicals. Structure and bonding Thioureas have a trigonal planar molecular geometry of the core. The bond distance is near 1.71 Å, which is 0.1 Å longer than in normal ketones (). The C–N bond distances are short. Thioureas occurs in two tautomeric forms. : On the other hand, some compounds depicted as isothioureas and in fact thioureas, one example being mercaptobenzimidazole. Synthesis ''N'',''N''′-unsubstituted thioureas can be prepared by treating the corresponding cyanamide with hydrogen sulfide or similar sulfide sources. Organic ammonium salts react with potassium thiocyanate as the source of the thiocarbonyl (). Alternatively, ''N'',''N''′-disubstituted thioureas can be prepared by coupling two amines with thiophosgen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the '' thio-'' prefix). The properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. Thioureas are a broad class of compounds with the formula Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such as isothiouronium salts. : Production The global annual production of thiourea is around 8,000 tonnes, mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea Functional Group
Thiourea () is an organosulfur compound with the chemical formula, formula and the Chemical structure, structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the ''thio-'' prefix). The properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. Thioureas are a broad class of compounds with the formula Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thioketone, thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such as isothiouronium salts. : Production The global annual production of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea Tautomers (cropped)
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the ''thio-'' prefix). The properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. Thioureas are a broad class of compounds with the formula Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such as isothiouronium salts. : Production The global annual production of thiourea is around 8,000 tonnes, mostly in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylene Thiourea
Ethylene thiourea (ETU) is an organosulfur compound with the formula . It is an example of an ''N'',''N''-disubstituted thiourea. It is a white solid. It is synthesized by treating ethylenediamine with carbon disulfide. Ethylene thioureas are an excellent accelerant of vulcanization of neoprene rubbers. In commercial use is the N,N'-diphenylethylenethiourea. Due to reproductive toxicity, carcinogenicity, and mutagenicity, alternatives are being sought to the ethylenethioureas. One candidate replacement is N-methyl-2-thiazolidinethione. Ethylene thiourea can be used as a biomarker of exposure to ethylenebisdithiocarbamates (EBDTCs), which are frequently employed as fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ...s in agriculture, mainly on fruits, vegetables and orna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylene Thiourea
Ethylene thiourea (ETU) is an organosulfur compound with the formula . It is an example of an ''N'',''N''-disubstituted thiourea. It is a white solid. It is synthesized by treating ethylenediamine with carbon disulfide. Ethylene thioureas are an excellent accelerant of vulcanization of neoprene rubbers. In commercial use is the N,N'-diphenylethylenethiourea. Due to reproductive toxicity, carcinogenicity, and mutagenicity, alternatives are being sought to the ethylenethioureas. One candidate replacement is N-methyl-2-thiazolidinethione. Ethylene thiourea can be used as a biomarker of exposure to ethylenebis dithiocarbamates (EBDTCs), which are frequently employed as fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ...s in agriculture, mainly on fruits, vegetables ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea Organocatalysis
Within the area of organocatalysis, (thio)urea organocatalysis describes the use of ureas and thioureas to accelerate and stereochemically alter organic transformations. The effects arise through hydrogen-bonding interactions between the substrate and the (thio)urea. Unlike classical catalysts, these organocatalysts interact by non-covalent interactions, especially hydrogen bonding ("partial protonation"). The scope of these small-molecule H-bond donors termed (thio)urea organocatalysis covers both non-stereoselective and stereoselective reactions. Catalyst-substrate interactions Hydrogen-bonding between thiourea derivatives and carbonyl substrates involve two hydrogen bonds provided by coplanar amino substituents in the (thio)urea. Squaramide catalysts engage in double H-bonding interactions and are often superior to thioureas. Thioureas are often found to be stronger hydrogen-bond donors (''i.e.,'' more acidic) than ureas because their amino groups are more positively charg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isothiouronium
In organic chemistry, isothiouronium is a functional group with the formula [RSC(NH2)2]+ (R = alkyl, aryl) and is the acid salt of isothiourea. The H centres can also be replaced by alkyl and aryl. Structurally, these cations resemble guanidinium cations. The CN2S core is planar and the C–N bonds are short. Synthesis Salts comprising these cations are typically prepared by alkylation of thiourea: :SC(NH2)2 + RX → [RSC(NH2)2]+X− Reactions Hydrolysis of isothiouronium salts gives thiols. :[RSC(NH2)2]+X− + NaOH → RSH + OC(NH2)2 + NaX Isothiouronium salts in which the sulfur has been alkylated, such as ''S''-methylisothiourea hemisulfate (CAS number: 867-44-7), will convert amines into guanidinium groups. This approach is sometimes called the Rathke synthesis after Bernhard Rathke who first reported it in 1881. : RNH2 + [CH3SC(NH2)2]+X− → [CH3N(H)C(NH2)2]+X− + CH3SH Chelating resins with isothiouronium groups are used to recover mercury and other noble metals in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercaptobenzimidazole
Mercaptobenzimidazole is the organosulfur compound with the formula C6H4(NH)2C=S. It is the mercaptan of benzimidazole. It is a white solid that has been investigated as a corrosion inhibitor. The name is a misnomer because the compound is a thiourea, characterized with a short C=S bond length of 169 pm. A similar situation applies to 2-mercaptoimidazole, which is also a thiourea properly called 2-imidazolidinethione and mercaptobenzothiazole, which is also a thioamide. It is prepared from o-phenylenediamine ''o''-Phenylenediamine (OPD) is an organic compound with the formula C6H4(NH2)2. This aromatic diamine is an important precursor to many heterocyclic compounds. OPD is a white compound although samples appear darker owing to oxidation by air. I ....{{cite journal , doi=10.15227/orgsyn.030.0056 , title=2-Mercaptobenzimidazole, journal=Organic Syntheses , date=1950 , volume=30 , page=56, first1=J. A. , last1=VanAllan, first2=B. D., last2= Deacon References Thioureas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiophosgene
Thiophosgene is a red liquid with the formula . It is a molecule with trigonal planar geometry. There are two reactive C–Cl bonds that allow it to be used in diverse organic syntheses. Preparation Typically, is prepared in a two-step process from carbon disulfide. In the first step, carbon disulfide is chlorinated to give trichloromethanesulfenyl chloride (), a rare sulfenyl chloride: : The chlorination must be controlled as excess chlorine converts trichloromethanesulfenyl chloride into carbon tetrachloride. Steam distillation separates the trichloromethanesulfenyl chloride and hydrolyzes the disulfur dichloride. Reduction of trichloromethanesulfenyl chloride with, e.g., tin or dihydroanthracene produces thiophosgene: : An alternative one-step reaction is :CCl4 + H2S → SCCl2 + 2 HCl Reactions is mainly used to prepare compounds with the connectivity where X = OR, NHR. Such reactions proceed via intermediate such as CSClX. Under certain conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiocyanates
Thiocyanates are salts containing the thiocyanate anion (also known as rhodanide or rhodanate). is the conjugate base of thiocyanic acid. Common salts include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyrotechnics. Thiocyanate is analogous to the cyanate ion, , wherein oxygen is replaced by sulfur. is one of the pseudohalides, due to the similarity of its reactions to that of halide ions. Thiocyanate used to be known as rhodanide (from a Greek word for rose) because of the red colour of its complexes with iron. Thiocyanate is produced by the reaction of elemental sulfur or thiosulfate with cyanide: : : The second reaction is catalyzed by thiosulfate sulfurtransferase, a hepatic mitochondrial enzyme, and by other sulfur transferases, which together are responsible for around 80% of cyanide metabolism in the body. Oxidation of thiocyanate inevitably produces hydrogen sulfate. The other product depend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities.. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transamidation
Transamidation is a chemical reaction in which an amide reacts with an amine to generate a new amide: :RC(O)NR'2 + HNR"2 → RC(O)NR"2 + HNR'2 The reaction is typically very slow, but it can be accelerated with Lewis acid and organometallic catalysts. Primary amides (RC(O)NH2) are more amenable to this reaction. Ureas In contrast to the reluctance of amides as substrates, urea is more susceptible to this exchange process. Transamidation is practiced, sometimes even on an industrial scale, to prepare a variety of N-substituted ureas: :(H2N)2CO + R2NH → (R2N)(H2N)CO + NH3 :(R2N)(H2N)CO + R2NH → (R2N)2CO + NH3 Methylurea, precursor to theobromine, is produced from methylamine and urea. Phenylurea is produced similarly but from anilinium chloride:{{cite journal , title=Arylureas II. Urea Method p-Ethoxyphenylurea , journal=Org. Synth. , year=1951 , volume=31 , page=11 , doi=10.15227/orgsyn.031.0011 :(H2N)2CO + 6H5NH3l → (C6H5(H)N)(H2N)CO + NH4C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
