- Synthesis method of benzimidazole compound based on iron catalytic oxidation-reduction coupling reaction
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The invention belongs to the field of organic synthesis, and relates to a benzimidazole compound synthesis method based on an iron catalytic oxidation-reduction coupling reaction. According to the method, o-nitroaniline compounds and alcohol compounds are used as raw materials, and the benzimidazole compounds are generated through iron-catalyzed redox coupling reaction in the presence of an iron catalyst and a proton donor. The method provided by the invention provides a new way for the synthesis of benzimidazole drugs and pesticides. Compared with a traditional benzimidazole compound synthesis method with o-phenylenediamine compounds and carboxylic acid or carboxylic acid derivatives as raw materials, the method has the advantages that the atom utilization rate of the whole process is increased, the production cost is reduced, and waste gas, waste liquid and waste solid generated in the production process is reduced.
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Paragraph 0140
(2020/10/05)
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- Synthesis method of crude carboxylic ester (by machine translation)
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The method is characterized in that the carboxylic ester and the ether are prepared by reacting a carboxylic ester with an ether at a certain temperature under the catalysis of a catalyst at a certain pressure for a certain time. (by machine translation)
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Paragraph 0021; 0022
(2020/08/09)
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- Ammonium Complexes of Orthoester Cryptands Are Inherently Dynamic and Adaptive
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Fluxional chemical species such as bullvalene have been a valuable source of inspiration and fundamental insight into the nature of chemical bonds. A supramolecular analogue of bullvalene, i.e., a "fluxional host-guest system", in which the ensemble of a well-defined host and guest is engaged in continuous, degenerate constitutional rearrangements, is still elusive, however. Here, we report experimental and computational evidence for guest-induced dynamic covalent rearrangements in the ammonium complexes of self-assembled orthoester cryptands. This unique behavior is made possible by the ammonium guest playing a dual role: it is sufficiently acidic to initiate dynamic covalent exchange reactions at the orthoester bridgeheads, and as a hydrogen bond donor it acts as a supramolecular template, governing the outcome of a multitude of possible intra- and intermolecular rearrangement reactions. One particularly striking example of inherent dynamic behavior was observed in host-guest complex [NH4+o-Me2-2.1.1], which spontaneously rearranged into the larger and thermodynamically more stable complex [NH4+o-Me2-2.2.1], even though this process led to the formation of poor host o-Me2-1.1.1 as a consequence of the excess of one subcomponent (diethylene glycol; "1" in our nomenclature). These inherently adaptive host-guest networks represent a unique platform for exploring the interrelationship between kinetic and thermodynamic stability. For instance, as a result of optimal NH4+ binding, complex [NH4+o-Me2-2.2.1] was found to be thermodynamically stable (negligible intermolecular rearrangements over weeks), whereas computational studies indicate that the compound is far from kinetically stable (intramolecular rearrangements).
- Wang, Xiang,Shyshov, Oleksandr,Han?eva?ki, Marko,J?ger, Christof M.,Von Delius, Max
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supporting information
p. 8868 - 8876
(2019/06/13)
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- Self-assembled orthoester cryptands: Orthoester scope, post-functionalization, kinetic locking and tunable degradation kinetics
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Dynamic adaptability and biodegradability are key features of functional, 21st century host-guest systems. We have recently discovered a class of tripodal supramolecular hosts, in which two orthoesters act as constitutionally dynamic bridgeheads. Having previously demonstrated the adaptive nature of these hosts, we now report the synthesis and characterization-including eight solid state structures-of a diverse set of orthoester cages, which provides evidence for the broad scope of this new host class. With the same set of compounds, we demonstrated that the rates of orthoester exchange and hydrolysis can be tuned over a remarkably wide range, from rapid hydrolysis at pH 8 to nearly inert at pH 1, and that the Taft parameter of the orthoester substituent allows an adequate prediction of the reaction kinetics. Moreover, the synthesis of an alkyne-capped cryptand enabled the post-functionalization of orthoester cryptands by Sonogashira and CuAAC "click" reactions. The methylation of the resulting triazole furnished a cryptate that was kinetically inert towards orthoester exchange and hydrolysis at pH > 1, which is equivalent to the "turnoff" of constitutionally dynamic imines by means of reduction. These findings indicate that orthoester cages may be more broadly useful than anticipated, e.g. as drug delivery agents with precisely tunable biodegradability or, thanks to the kinetic locking strategy, as ion sensors.
- L?w, Henrik,Mena-Osteritz, Elena,Von Delius, Max
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p. 4785 - 4793
(2018/06/07)
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- Orthoester exchange: A tripodal tool for dynamic covalent and systems chemistry
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Reversible covalent reactions have become an important tool in supramolecular chemistry and materials science. Here we introduce the acid-catalyzed exchange of O,O,O-orthoesters to the toolbox of dynamic covalent chemistry. We demonstrate that orthoesters readily exchange with a wide range of alcohols under mild conditions and we disclose the first report of an orthoester metathesis reaction. We also show that dynamic orthoester systems give rise to pronounced metal template effects, which can best be understood by agonistic relationships in a three-dimensional network analysis. Due to the tripodal architecture of orthoesters, the exchange process described herein could find unique applications in dynamic polymers, porous materials and host-guest architectures.
- Brachvogel, Ren-Chris,Von Delius, Max
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p. 1399 - 1403
(2015/02/05)
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- Transesterification of trimethyl orthoacetate: An efficient protocol for the synthesis of 4-alkoxy-2-aminothiophene-3-carbonitriles
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A facile one-pot method is reported for the synthesis of 4-alkoxy-2-aminothiophene-3-carbonitriles. Transesterification of trimethylorthoacetate technique allowed introducing alkoxy substituents into 2-aminothiophene ring system. Diverse alkoxy substituents could be introduced efficiently by using this methodology. Further the synthesis of some of new 4-alkylamino-2-aminothiophenes is also reported.
- Venkata Rao,Balakumar,Lakshmi Narayana,Pran Kishore,Rajwinder,Raghuram Rao
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supporting information
p. 1274 - 1278
(2013/03/13)
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- Novel substituted (4.2.0)bicyclooctane derivatives with valuable therapeutic properties
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Compounds useful in treating cardiovascular disorders such as thrombosis, hypertension and atherosclerosis are depicted in formulas (1), (2) and (3): STR1 wherein: A is --C C--, trans --HC=CH--, --CH2 CH2 -- or --CH=CHCH2 --; X is lower alkoxy, hydroxy, or (2,2,2)-trifluoroethoxy; Y is hydrogen, exo-(lower alkyl) or endo-(lower alkyl); is an integer of 2-4; R1 is --CH2 OH, --CHO, --CO2 R or --CO2 H, and the olefin formed by the R1 (CH2)n CH= moiety is either (E) or (Z); R2 is hydrogen or methyl, or optionally --CH=CH2 when A is --CH=CHCH2 --; and R3 is linear or branched alkyl, alkenyl or alkynyl having 5-10 carbon atoms, STR2 --(CH2)m -phenyl or CH2 O-phenyl; in which each phenyl may be optionally substituted with lower alkyl, lower alkoxy, trifluoromethyl, or halogen; in which: a is an integer of 0, 1 or 2; b is an integer of 3-7; m is an integer of 0, 1 or 2; and R is STR3 wherein x is STR4 in which each R4 is independently hydrogen or lower alkyl having 1-6 carbon atoms, and the pharmaceutically acceptable, non-toxic salts and esters thereof.
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- Novel 8-(lower alkyl)bicyclo[4.2.0]octane derivatives with valuable therapeutic properties
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Compounds useful in treating cardiovascular disorders such as thrombosis, hypertension, and atherosclerosis are compounds depicted in formulas (1), (2), and (3): STR1 wherein: Y is exo-(lower alkyl) or endo-(lower alkyl); n is 2 or 3; R1 is CH2 OH, CHO, CO2 R or CO2 H; R2 is hydrogen or methyl; and R3 is linear or branched alkyl having 5-10 carbon atoms, STR2 or --(CH2)m -phenyl optionally substituted with lower alkyl, lower alkoxy, trifluoromethyl, or halogen, in which a is 0, 1 or 2; b is 3-7; m is 1 or 2; and R is STR3 wherein X is STR4 in which each R4 is independently hydrogen or lower alkyl having 1-6 carbon atoms, and the pharmaceutically acceptable, non-toxic salts and esters thereof.
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- THERMAL AND PHOTOCHEMICAL REACTIONS OF BIACETYL WITH 1,1-DIETHOXYETHENE. "UMPOLUNG" OF THE REACTIVITY OF BIACETYL BY PHOTOCHEMICAL INDUCED ELECTRON TRANSFER.
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The thermal and photochemical reactions of biacetyl 1 and 1,1-diethoxyethene 2 are totally complementary: 1 and 2 exclusively form the 2,2-diethoxyoxetane 4 in polar solvents at room temperature.Contrary to the literature this thermal cycloaddition proceeds uncatalyzed. 1 and 2 react photochemically under exclusive formation of the regioisomer oxetane 3 - preferably in nonpolar solvents.The inversion ("Umpolung") of the reactivity of 1 is caused by the photoinduced electron transfer.
- Mattay, Jochen,Gersdorf, Joachim,Freudenberg, Ulrich
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p. 817 - 820
(2007/10/02)
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- Method of preparing orthoacetic acid alkyl esters
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An improvement in the process for preparing an orthoacetic acid alkyl ester of the formula STR1 wherein R is a saturated, branched or un-branched, alkyl moiety of 1 to 8 carbon atoms by: (a) contacting acetonitrile with an anhydrous alkanol having 1 to 8 carbon atoms and dry hydrogen chloride in the presence of an organic solvent to prepare the corresponding imidoester hydrochloride; (b) thereafter contacting said imidoester hydrochloride in the acid-free state with an alkanol having 1 to 8 carbon atoms; and (c) removing by-product ammonium chloride from the resultant reaction mixture and distilling the reaction mixture to recover orthoacetic acid alkyl ester, the improvement residing in (d) employing as the organic solvent an inert solvent having a dielectric constant measured at 25° C. of 2.6 or less; and (e) contacting said imidoester hydrochloride in step (b) with an alkali metal or alkaline earth metal alcoholate before contacting the same with said alkanol. Also disclosed is a process in which steps (a) and (b) are performed coterminously without isolation or recovery of the intermediate imidoester hydrochloride.
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- On the Mechanism of Acetalization Reactions with Carboxamide-Dialkyl Sulfate Adducts; a New Method of Preparation of Orthocarboxylic Esters and of Cleavage of Carboxamides.
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It is shown that the efficiency of carboxamide-dialkyl-sulfate adducts in acetalization reactions depends on their alkylation ability.A mechanism of acetal formation using orthoformates as acetalization reagents is proposed.Alcoholysis of carboxamide-dialkyl sulfate adducts 1b, 11, 13 affords orthocarboxylic esters.Carboxamides and carboxmorpholides react with dimethyl sulfate/methanol to give methyl esters.
- Kantlehner, Willi,Gutbrod, Heinz-Dieter
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p. 1677 - 1688
(2007/10/02)
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