- A more sustainable isothiocyanate synthesis by amine catalyzed sulfurization of isocyanides with elemental sulfur
-
Isothiocyanates (ITCs) are typically prepared using amines and highly toxic reagents such as thiophosgene, its derivatives, or CS2. In this work, an investigation of a multicomponent reaction (MCR) using isocyanides, elemental sulfur and amines revealed that isocyanides can be converted to isothiocyanates using sulfur and catalytic amounts of amine bases, especially DBU (down to 2 mol%). This new catalytic reaction was optimized in terms of sustainability, especially considering benign solvents such as Cyrene or γ-butyrolactone (GBL) under moderate heating (40 °C). Purification by column chromatography was further optimized to generate less waste by maintaining high purity of the product. Thus, E-factors as low as 0.989 were achieved and the versatility of this straightforward procedure was shown by converting 20 different isocyanides under catalytic conditions, while obtaining moderate to high yields (34-95%). This journal is
- Nickisch,Conen,Gabrielsen,Meier
-
p. 3134 - 3142
(2021/01/28)
-
- 2-(aryl (azacycloalkane-1-yl) methyl) phenol derivatives and uses thereof
-
The invention discloses 2-(aryl (azacycloalkane-1-yl) methyl) phenol derivatives and application thereof, and belongs to the technical field of medicines. The invention provides a compound shown in a formula I or pharmaceutically acceptable salt thereof. The series of compounds have good inhibitory activity on the histone demethylase KDM4 family in vitro, the median inhibitory concentration (IC50) of most molecules on KDM4D is less than 500 nM, and the compounds have good inhibitory effect on proliferation of various human tumor cell strains in vitro, so that the series of compounds provide a new effective choice for developing targeted histone demethylase KDM4D drugs and preparing drugs for treating and/or preventing cancers and reproductive system diseases, and have good application prospects.
- -
-
Paragraph 0309-0311
(2021/07/24)
-
- Preparation method of isothiocyano compound
-
The invention discloses a preparation method of an isothiocyano compound. An ammonium thiocyanate, sodium thiocyanate or potassium thiocyanate water solution and a halide are used as raw materials, and an isothiocyano compound is synthesized under the action of a phase transfer catalyst. The requirements that the thiocyanate radical in each batch of reaction is excessive by 10% and the yield is high are met, the purpose that the concentration of thiocyanic acid in wastewater is very low is realized, complex wastewater treatment equipment and treatment operation are avoided, and environmental protection pressure is reduced. The preparation method is a green preparation method, and solves the problems of extremely difficult degradation and high biotoxicity of thiocyanate-containing wastewater in conventional isothiocyano compound production. The method is simple to operate and is suitable for industrial production.
- -
-
Paragraph 0014
(2019/10/29)
-
- Preparation method of buprofezin
-
The invention provides a preparation method of buprofezin, comprising the steps of 1), adding sodium thiocyanate and water into an esterification kettle until dissolution; adding tertiary butanol andhydrochloric acid to obtain a mixed ester; allowing transposition and catalytic reaction to obtain t-butyl isothiocyanate; 2), adding the t-butyl isothiocyanate into chlorobenzene, stirring, dropwiseadding isopropyl amine to obtain 1-isopropyl-3-tert-butylthiourea solution; 3), adding N-methylaniline into chlorobenzene; introducing carbonyl chloride and chlorine gas in sequence to obtain N-chloromethyl-N-benzenecarbamoylchloride solution; 4), adding sodium bicarbonate into water, and adding the resultant into chlorobenzene; adding the 1-isopropyl-3-tert-butylthiourea solution; dropwise addingthe N-chloromethyl-N-benzenecarbamoylchloride solution, filtering, allowing layering, performing high-vacuum steaming to remove the chlorobenzene, crystallizing, centrifuging, and drying to obtain buprofezin. The substitutive average yield of the preparation process of buprofezin reaches 90% and above; the content of finished buprofezin reaches 98.0% and above; the preparation process is free ofammonia nitrogen wastewater.
- -
-
Paragraph 0024; 0026; 0027
(2018/10/11)
-
- Na2S2O8-mediated efficient synthesis of isothiocyanates from primary amines in water
-
We have developed two green, practical, and efficient procedures, including a one-pot one, to synthesize isothiocyanates from amines and carbon disulfide via desulfurization with sodium persulfate. Water is used as the solvent. Basic conditions are necessary for good chemoselectivity for isothiocyanates. Structurally diverse linear and branched alkyl amines and aryl amines are readily converted to isothiocyanates by the two procedures in satisfactory yields. Halogens, benzylic C-H bonds, methylthio, nitro, ester, alkenyl, electron-rich or -deficient (hetero)aryls, acetylenyl, and even phenolic and alcoholic hydroxyls are well tolerated. The one-pot procedure in water can also be used to realize the preparation of chiral isothiocyanates from chiral amines, and the modification of bioactive structures with free amino groups. In large-scale preparation, simple and practical purification procedures independent of column chromatography are developed.
- Fu, Zhicheng,Yuan, Wenhao,Chen, Ning,Yang, Zhanhui,Xu, Jiaxi
-
supporting information
p. 4484 - 4491
(2018/10/17)
-
- Synthesis of Isothiocyanates and Unsymmetrical Thioureas with the Bench-Stable Solid Reagent (Me4N)SCF3
-
A highly efficient, selective, and rapid transformation of primary amines and diamines to isothiocyanates and cyclic thioureas is disclosed. As opposed to established approaches that employ toxic or volatile electrophilic liquids and require reaction control (i.e., slow addition, cooling), this protocol utilizes the bench-stable, solid reagent (Me4N)SCF3 at room temperature. The method is characterized by operational simplicity, high speed, efficiency, high functional group tolerance, and late-stage applicability. The byproducts are solids, allowing isolation of the target compounds by filtration.
- Scattolin, Thomas,Klein, Alexander,Schoenebeck, Franziska
-
supporting information
p. 1831 - 1833
(2017/04/11)
-
- 4,5-Disubstituted N-Methylimidazoles as Versatile Building Blocks for Defined Side-Chain Introduction
-
Fungerin is a 1,4,5-trisubstituted imidazole natural product characterised by a broad spectrum of antifungal activities. We planned to develop flexible strategies to access to such compounds. Imidazoles bearing suitable anchor groups at C-4 and C-5 allow the introduction of various substituted side-chains, generating libraries of fungerin derivatives for biological tests. Starting from commercially available reactants, two N-methyl 4,5-substituted imidazole core units were synthesised. Derivatives of type 1 contained two orthogonally protected C-1 anchors. Selective side-chain introduction was achieved through a sequence of Grignard coupling at C-5 to replace a tosylate and a Horner olefination through an aldehyde attached to C-4. Two target fungerin derivatives were synthesised. Since the organometallic substitution of the C-5-CH2-positioned leaving group proved to suffer from limitations concerning potential competing side-reactions, a type 2 imidazole core was built up. These structures had a halogen centre at C-4 and a hydroxyethyl anchor at C-5. Now, selective side-chain introduction allowed us to use Julia olefination to form the allyl side-chain at C-5 and Heck reactions to introduce the C-4 acryl substituents. Eight derivatives, including fungerin, were synthesised by this latter strategy, without producing any regioisomers. The second approach had the advantage that various side-chains could be coupled at C-4 and C-5 in two final steps. Thus, this strategy represents a versatile way to build up libraries of fungerin derivatives for biological testing.
- Przybyla, Daniel,Nubbemeyer, Udo
-
supporting information
p. 695 - 703
(2017/02/05)
-
- Catalytic Production of Isothiocyanates via a Mo(II)/Mo(IV) Cycle for the "soft" Sulfur Oxidation of Isonitriles
-
In the presence of excess amounts of elemental sulfur, the dimolybdenum dinitrogen complex {CpMo[N(iPr)C(Ph)N(iPr)]}2(μ-N2) (4; Cp? = η5-C5Me5) serves as a precatalyst for the production of isothiocyanates from isonitriles via highly efficient and atom-economical metal-mediated sulfur atom transfer (SAT) under mild conditions. Mechanistic and structural studies support a catalytic cycle for SAT involving initial formation of a Mo(II) bis(isonitrile) complex that then undergoes sulfination to generate a formal "side-bound" Mo(IV) κ 2-(C,S)-isothiocyanate as the key intermediate. This metal-catalyzed SAT process has further been employed for the "on-demand" production of isothiocyanates that are trapped in situ by benzhydrazides to provide thiosemicarbazides, which are useful precursors to biologically active thiadiazoles.
- Farrell, Wesley S.,Zavalij, Peter Y.,Sita, Lawrence R.
-
supporting information
p. 2361 - 2366
(2016/08/02)
-
- Double three bromo 1,3-di-pyridine salt-based propane and its preparation method, method of use, recovery method and application
-
The invention discloses a double tribromo 1,3-bipyridine onium salt dimethylmethane, and a preparation method, an application method, a recovery method and application thereof. The preparation method comprises the following steps: dissolving 1,3-bipyridine onium salt dimethylmethane by using water, and then adding potassium bromide; adding potassium peroxymonosulfate sulfate compound brine solution to prepare a clear solution after dissolving potassium bromide, and then stirring and reacting at -10 to 0 DEG C until solid is separated out; separating out solid, so as to obtain the double tribromo 1,3-bipyridine onium salt dimethylmethane. The product can be used for preparing isothiocyanate, aromatic thiourea or acetanilide. The preparation method disclosed by the invention is mild in condition, and simple to operate the reaction process, and raw materials are easily available. The double tribromo 1,3-bipyridine onium salt dimethylmethane not only can be used as a brominating reagent, but also can be used as organic synthesis intermediates, meanwhile, the reaction efficiency is improved, and the double tribromo 1,3-bipyridine onium salt dimethylmethane is convenient to recover and can be recycled.
- -
-
Paragraph 0075; 0076; 0200; 0201
(2016/10/07)
-
- Purification-Free, Small-Scale Synthesis of Isothiocyanates by Reagentless Fragmentation of Polymer-Supported 1,4,2-Oxathiazoles
-
The synthesis of isothiocyanates (ITCs) by employing polymer-supported 1,4,2-oxathiazoles is described. The ITCs are obtained in moderate yields and high purity through a reagentless, thermal fragmentation of polymer-supported 1,4,2-oxathiazoles that are obtained by trapping nitrile oxides with polymer-supported thiocarbonates. A purification-free, small-scale synthesis for isothiocyanates (ITCs) is reported that proceeds through a catch-and-release system. This is a convenient method to produce small quantities of ITCs in high purity for screening purposes.
- Burkett, Brendan A.,Fu, Pincheng,Hewitt, Russell J.,Ng, Su Ling,Toh, Joel D. W.
-
p. 1053 - 1058
(2015/10/05)
-
- Purification-free, small-scale synthesis of isothiocyanates by reagentless fragmentation of polymer-supported 1,4,2-oxathiazoles
-
The synthesis of isothiocyanates (ITCs) by employing polymer-supported 1,4,2-oxathiazoles is described. The ITCs are obtained in moderate yields and high purity through a reagentless, thermal fragmentation of polymer-supported 1,4,2-oxathiazoles that are obtained by trapping nitrile oxides with polymer-supported thiocarbonates. A purification-free, small-scale synthesis for isothiocyanates (ITCs) is reported that proceeds through a catch-and-release system. This is a convenient method to produce small quantities of ITCs in high purity for screening purposes. Copyright
- Burkett, Brendan A.,Fu, Pincheng,Hewitt, Russell J.,Ng, Su Ling,Toh, Joel D. W.
-
p. 1053 - 1058
(2014/03/21)
-
- Microwave-assisted synthesis of alkyl thiocyanates
-
Microwave irradiation accelerated the reaction of t-alkyl, allyl, and benzyl halides with Zn(SCN)2 to afford thiocyanates in excellent yields and high selectivity with the formation of isothiocyanates only in minor proportions. Because thiocyanates are stable intermediates to thiols, the method also affords facile access to corresponding thiols.
- Bound, D. James,Bettadaiah,Srinivas
-
p. 1138 - 1144
(2013/03/28)
-
- A general and facile one-pot process of isothiocyanates from amines under aqueous conditions
-
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
-
experimental part
p. 61 - 70
(2012/04/04)
-
- 1-tert-Butyl-1H-tetrazol-5-yl fluoromethyl sulfone (TBTSO2CH2F): A versatile fluoromethylidene synthon and its use in the synthesis of monofluorinated alkenes via JuliaKocienski olefination
-
1-tert-Butyl-IH-tetrazol-5-yl fluoromethyl sulfone (TBTSO 2CI-12F) has been developed as a new and efficient fluoromethylidene synthon for the synthesis of both terminal and internal monofluoroalkenes via JuliaKocienski olefination reaction. The base-mediated reaction between TBTSO2CI-12F and carbonyl compounds (aldehydes and ketones) provided terminal monofluoroalkenes in good yields with moderate E!Z selectivity. The dominance of E- or Z-fluoroalkenes could be controlled by selection of proper reaction solvent and temperature. TBTSO 2CI-12F reagent was also found to be readily CL-alkylated, acylated, and phenylsulfonylated to give corresponding CL-functionalized fluorosulfones, which could be used in the synthesis of alkyl-, acyl-, and phenylsulfonyl-substituted internal monofluoroalkenes via JuliaKocienski olefination reactions.
- Zhu, Lingui,Ni, Chuanfa,Zhao, Yanchuan,Ru, Jinbo
-
supporting information; experimental part
p. 5089 - 5100
(2010/08/20)
-
- A simple organocatalytic enantioselective synthesis of pregabalin
-
This paper describes a new procedure for the enantioselective synthesis of the important anticonvulsant drug Pregabalin, which shows biological properties as the (S) enantiomer only. The key step of the synthetic sequence is the Michael addition reaction of Meldrum's acid to a nitroalkene mediated by a quinidine derived thiourea. A variety of novel catalysts bearing different groups at the thiourea moiety were synthesized and tested. The most successful catalyst that incorporates a trityl substituent provided up to 75 % ee of (S)- 4. The conjugate addition reaction was carried out on a multigram scale with low loadings of catalyst (10 mol-%). Moreover, the catalyst can be recycled showing the same capability in chemical yield and asymmetric induction. Then, hydrogenation of nitroalkane 4 followed by decarboxylation of diacid 5 provides Pregabalin hydrochloride in 59% overall yield. Enantioenrichment by crystallization of the free amino acid 1 improves the (S)/(R) enantiomeric ratio to 9:1. ? Wiley-VCII Verlag GmbH & Co. KGaA.
- Bassas, Oriol,Huuskonen, Juhani,Rissanen, Kari,Koskinen, Ari M.P.
-
experimental part
p. 1340 - 1351
(2009/07/26)
-
- Substituted urea/thiourea derived from fluoxetine as potent appetite suppressants
-
A series of urea and thiourea analogues of fluoxetine (5-17) were synthesized and evaluated for their anorexigenic and antidepressant activities. The related conformationally restrained analogues (20-23) were also prepared for structure-activity relationship (SAR) studies. Many of these derivatives (5, 6, 8, 10, 12, 13, 16, and 23) exhibited significant anorexigenic activity and interestingly were devoid of antidepressant activity, thus emerging as a promising tool for further research work.
- Bhandari, Kalpana,Srinivas, Nagarapu,Sharma, Lata,Srivastava, Shipra,Nath, Amar,Nath, Chandishwar
-
p. 103 - 113
(2008/12/22)
-
- A facile and new approach to synthesize 2-amino-4-(4-amoinophenyl)-1H-1,3- diazol-1-yl-alkylaminomethanethiones
-
An "intellectual connection" approach to design a facile and new synthesis of suitably substituted 2-aminoimidazole-based precursors of expected anti-asthmatic agents through a benzidine type of rearrangement of 2-phenylazoimidazole and subsequent coupling of the product thus obtained with alkylisothiocyanates involving a degenerative operation, thereby improving the time frame of the overall synthetic sequence, is reported. The alkylisothiocyanates required in this synthetic sequence are prepared using a best combination of reported methods. The compounds reported here can be used to produce derivatives of other biological agents. Birkhaeuser 2007.
- Verma, Raman K.,Aggarwal, Monika,Bansal, Manisha,Kaur, Inder Preet
-
p. 483 - 491
(2008/04/01)
-
- Polymer-supported thiobenzophenone: a self-indicating traceless 'catch and release' linker for the synthesis of isothiocyanates
-
The use of a thiobenzophenone as a self-indicating linker in the polymer-supported synthesis of isothiocyanates via a traceless 'catch and release' strategy is reported. Isothiocyanates were furnished via 1,3-dipolar cycloaddition of nitrile oxides with the polymer-supported thiobenzophenone linker, followed by Lewis acid-assisted fragmentation of the resulting polymer-supported oxathiazole.
- Burkett, Brendan A.,Kane-Barber, Jacqueline M.,O'Reilly, Robert J.,Shi, Lei
-
p. 5355 - 5358
(2008/02/10)
-
- Alkanethioimidoyl Radicals: Evaluation of β-Scission Rates and of Cyclization onto S-Alkenyl Substituents
-
Thioimidoyl radicals were generated by addition of alkylsulfanyl radicals to alkyl isonitriles and were characterized by electron paramagnetic resonance (EPR) spectroscopy. The β-scissions of their C·S-C bonds were studied by variable-temperature EPR spectroscopy and the fragmentation rate constants and activation energies were calculated. The scission rates depend on the stability of the released alkyl radicals but in any case, at room temperature, the processes were fast. Data collected on similar oxyimidoyls showed that their fragmentations are slightly slower compared to those of analogous thioimidoyls. The scission rates of selenoimidoyls could not be studied by EPR and were evaluated by theoretical calculations. EPR experiments also enabled both β-scission and 5-exo ring closure rate constants of two S-but-3-enyl-substituted imidoyl radicals to be determined, showing that cyclization prevails only at low temperatures. Density functional theory (DFT) theoretical calculations predicted that the fragmentation process preferentially occurs from the s-cis rotamers (X-C bond) of the imidoyl radicals. Thio- and seleno-imidoyls (but not oxyimidoyls) prefer s-trans conformations so that their fragmentations involve prior rotation about the X-C bond.
- Minozzi, Matteo,Nanni, Daniele,Walton, John C.
-
p. 2056 - 2069
(2007/10/03)
-
- Conversion of Alcohols, Thiols, Carboxylic Acids, Trimethylsilyl Ethers, and Carboxylates to Thiocyanates with Triphenylphosphine/ Diethylazodicarboxylate/NH4SCN
-
A novel and highly selective method is described using triphenylphosphine/ diethylazodicarboxylate (DEAD)/NH4SCN for the conversion of alcohols, thiols, carboxylic acids, silyl ethers, and silyl carboxylates to their corresponding thiocyanates.
- Iranpoor, Nasser,Firouzabadi, Habib,Akhlaghinia, Batool,Azadi, Roya
-
-
- Ultrasound-assisted nucleophilic substitution reaction of t-Alkyl halides with zinc and titanium thiocyanate
-
Ultrasound promotes nucleophilic substitution of t-alkyl halides with ambident thiocyanate nucleophile, in the form of its zinc or titanium thiocyanate, under mild conditions to afford the corresponding thiocyanates selectively, in good to excellent yields. This improved synthetic methodology affords a facile access to tertiary thiols via the corresponding thiocyanate intermediates.
- Bettadaiah,Gurudutt,Srinivas
-
p. 2293 - 2299
(2007/10/03)
-
- Direct synthesis of isothiocyanates from isonitriles by molybdenum-catalyzed sulfur transfer with elemental sulfur
-
The direct molybdenum-catalyzed sulfuration of a variety of isonitriles with elemental sulfur or propene sulfide as sulfur donors affords the corresponding isothiocyanates in good yields and under mild reaction conditions. A catalytic cycle is suggested, in which the molybdenum oxo disulfur complex operates as the active sulfur-transferring species. A novel adduct between the isonitrile and the molybdenum complex has been characterized by X-ray analysis and its association constant determined by UV-vis spectroscopy, but this adduct appears not to be involved in the sulfur-transfer process.
- Adam, Waldemar,Bargon, Rainer M.,Bosio, Sara G.,Schenk, Wolfdieter A.,Stalke, Dietmar
-
p. 7037 - 7041
(2007/10/03)
-
- Synthesis of some new thiocarbamides from a constituent of lac and studies on their antimicrobial activities
-
Some new thiocarbamides have been synthesized by the reaction of aleurityl hydrazide (prepared from aleuritic acid isolated from Bangladeshi lac) with different isothiocyanates. Antibacterial activities of the compounds have been determined and most of them are found highly active.
- Haque, M. Zahurul,Faruq, M. Omar,Ali, M. Umar
-
p. 841 - 842
(2007/10/03)
-
- A convenient synthesis of isothiocyanates from nitrile oxides
-
Isothiocyanats were prepared in quantitative yields from the reaction of nitrile oxides with thiourea in tetrahydrofuran at room temperature in short time.
- Kim, Jae Nyoung,Ryu, Eung K.
-
p. 8283 - 8284
(2007/10/02)
-
- A marvelous catalysis of tellurium in the formation of isothiocyanates from isocyanides and sulfur
-
Catalytic activity of tellurium in the formation of isothiocyanates from isocyanides and sulfur has been found to be extremely high and far superior to that of selenium.
- Fujiwara, Shin-Ichi,Shin-Ike, Tsutomu,Okada, Kazuhiro,Aoki, Minoru,Kambe, Nobuaki,Sonoda, Noboru
-
p. 7021 - 7024
(2007/10/02)
-
- Novel selenium catalyzed synthesis of isothiocyanates from isocyanides and elemental sulfur
-
A variety of aliphatic and aromatic isothiocyanates were synthesized in good to excellent yields from corresponding isocyanides and elemental sulfur under mild conditions by use of catalytic amounts of elemental selenium.
- Fujiwara, Shin-Ichi,Shin-Ike, Tsutomu,Sonoda, Noboru,Aoki, Minoru,Okada, Kazuhiro,Miyoshi, Noritaka,Kambe, Nobuaki
-
p. 3503 - 3506
(2007/10/02)
-
- Synthesis of isothiocyanates by reaction of amides with carbon disulfide in the presence of solid potassium carbonate/sodium hydroxide mixture
-
Readily available N-monosubstituted trifluoroacetamides are transformed into isothiocyanates in good yield by reaction, at room temperature, with carbon disulfide in acetonitrile in the presence of anhydrous sodium hydroxide/potassium carbonate basic mixture.
- Albanese,Penso
-
p. 1001 - 1002
(2007/10/02)
-
- A Convenient Synthesis of Tertiary Isothiocyanates and Acyl Isothiocyanates Using Phosphoryl Isothiocyanate.
-
Phosphoryl iosthiocyanate, PO(NCS)3, reacts readily with tertiary alcohols and carboxylic acids, giving the respective tertiary isothiocyanates and acyl isothiocyanates in good yields and purity.
- Kniezo, Ladislav,Bernat, Juraj
-
p. 509 - 513
(2007/10/02)
-
- Support-controlled Switching of Sulphur-Nitrogen Nucleophilicity for Inorganic Solid-supported Alkaline Earth Metal Thiocyanate Reagents
-
A dramatic change in the sulphur-nitrogen selectivity of the SCN substitution of t-butyl bromide was observed, in addition to a dramatic increase in reaction rate, by simply supporting various alkaline earth metal thiocyanates on various inorganic solids.
- Kimura, Takahide,Fujita, Mitsue,Ando, Takashi
-
p. 1213 - 1214
(2007/10/02)
-
- 1,1'-Thiocarbonyldi-2,2'-pyridone. A New Useful Reagent for Functional Group Conversions under Essentially Neutral Conditions
-
1,1'-Thiocarbonyldi-2,2'-pyridone is a useful reagent for the preparation of nitriles, carbodiimides, cyclic thionocarbonates, and isothiocyanates and deoxygenation of alcohols under essentially neutral conditions.
- Kim, Sunggak,Yi, Kyu Yang
-
p. 2613 - 2615
(2007/10/02)
-
- DI-2-PYRIDYL THIONOCARBONATE. A NEW REAGENT FOR THE PREPARATION OF ISOTHIOCYANATES AND CARBODIIMIDES.
-
Reaction of amines with di-2-pyridyl thionocarbonate affords the corresponding isothiocyanates at room temperature, while reaction of N,N'-disubstituted thioureas with di-2-pyridyl thionocarbonate in the presence of 4-dimethylaminopyridine as a catalyst affords the corresponding carbodiimides in high yields.
- Kim, Sunggak,Yi, Kyu Yang
-
p. 1661 - 1664
(2007/10/02)
-
- Synthesis and Properties of a Series of Sterically Hindered Guanidine Bases
-
By the reaction of Vilsmeier salts, derived from tetra-alkylureas or from tetra-alkylthioureas, with primary aliphatic amines, a series of sterically hindered penta-alkyl guanidines has been prepared. 2-t-Butyl-1',1',3'',3''-tetramethylguanidine and pentaisopropylguanidine combine ease of preparation with a range of resistance to alkylating agents.Preliminary experiments indicate that these inexpensive bases will useful in organic synthesis.
- Barton, Derek H. R.,Elliott, John D.,Gero, Stephan D.
-
p. 2085 - 2090
(2007/10/02)
-
- A Method for the Simultaneous Preparation of Alkyl Isothiocyanates and Thiols
-
Aus primaeren Alkylaminen wurden Ethyl-, Butyl-, Isobutyl- und n-Dodecyldithiocarbamate 2 hergestellt.Letztere lassen sich leicht zu den Isothiocyanaten 3 und Thiolen 4 pyrolisieren.Die Massenspektren der Ester sowie deren Pyrolyseprodukte wurden gemessen.
- Blotny, Grzegorz
-
p. 1927 - 1932
(2007/10/02)
-
- Cephem derivative
-
Cephem derivatives of the general formula STR1 in which the R2 O group is in the syn-position, a process for their manufacture and pharmaceutical formulations which are active against bacterial infections and contain these compounds.
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-
- REACTIONS OF 2-(TERT-BUTYLIMINO)-3-METHYL-4-TOSYLIMINO-1,3-THIAZETIDINE
-
This paper describes the reactivity of the title bis(imino)thiazetidine in terms of three reactivity centers of the molecule; C2, C4 and C=NTs.Reactions have been carried out with nucleophilic reagents (NaOMe, NaSEt, KCN and malonic ester/DMSO/NaH), hydrazoic acid and electron-rich olefins (enamines and ynamines), giving rise to products 2-10.The two products, 9 and 10, obtained in equal amounts from 1 and N,N-diethylaminopropyne have been subjected to a detailed analysis by spectral methods and the structure of one of them (10) has been confirmed by the determination of its crystal structure.
- Sorgeloos, Dominique,Toppet, Suzanne,King, Geoffrey S. D.,Meervelt, Luc Van
-
-
- Acylcarbodiimides, IV. Preparation and Some Reactions of Carbamoylcarbodiimides
-
Starting from carbamoyl-thioureas (1) and with the aid of cyanuric trichloride/triethylamine several carbamoylcarbodiimides (2) were prepared.In the case of aryl-substituted 1, elimination of arylamine competed with that of hydrogen sulfide.Rearrangement of a guanyl isocyanate (6) formed in situ afforded 2a on another way.Many carbodiimides 2 add water and other protic nucleophiles very rapidly.The exact structure of the adducts 7 - 9 is discussed.
- Goerdeler, Joachim,Raddatz, Siegfried
-
p. 1095 - 1105
(2007/10/02)
-
- 5-Heterocyclic-1,2,3,6-tetrahydro-4(5H) pyrimidinone
-
The compounds of this invention are 5-heterocyclic-1,2,3,6-tetrahydro-4(5H)-pyrimidinethiones which have pharmacological activity, in particular gastric acid secretion inhibitory activity, and 5-heterocyclic-1,2,3,6-tetrahydro-4(5H)-pyrimidinones which are intermediates in the preparation therefor.
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