- 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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- 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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- An efficient synthesis of 2,6-disubstituted benzobisoxazoles: New building blocks for organic semiconductors
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(Chemical Equation Presented) 2,6-Disubstituted benzobisoxazoles have been synthesized by a highly efficient reaction of diaminobenzene diols with various orthoesters. The scope of this new reaction for the synthesis of substituted benzobisoxazoles has been investigated using four different orthoesters. The utility of these compounds as building blocks for the synthesis of conjugated polymers is demonstrated.
- Mike, Jared F.,Makowski, Andrew J.,Jeffries-El, Malika
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supporting information; experimental part
p. 4915 - 4918
(2009/05/31)
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- Process for the production of 2-Chloro-1,1,1-trialkoxyethane
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Preparation of 2-chloro-1,1,1-trialkoxyethane involves reacting 1,1,1-trialkoxyethane with gaseous or liquid chlorine in the presence of alcohol solvent (0.1-20 wt.%) based on the amount of 1,1,1-trialkoxyethane reactant. Preparation of 2-chloro-1,1,1-trialkoxyethane of formula Cl-CH2-C(OR1)(OR2)(OR3) (I) involves reacting 1,1,1-trialkoxyethane with gaseous or liquid chlorine in the presence of alcohol solvent (preferably 1-10C) (0.1-20, preferably 5-20) wt.% based on the amount of 1,1,1-trialkoxyethane. R1-R3 = alkyl; R1+R2, R2+R3 and R1+R3 = a cyclic group.
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- Synthesis of optically active 2-chloromethyl-2-oxazolines by the ortho- ester condensation method using triethyl orthochloroacetate
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A set of optically active 2-chloromethyl-2-oxazolines was synthesized by condensation of optically active 2-amino alcohols with triethyl orthochloroacetate which was prepared conveniently from triethyl orthoacetate by chlorination using tert-butyl hypochlorite.
- Kamata, Kazuyuki,Sato, Hideki,Takagi, Emi,Agata, Isao,Meyers
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p. 373 - 378
(2007/10/03)
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- Synthesis and evaluation of antiinflammatory activities of a series of corticosteroid 17α-esters containing a functional group
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A series of 21-desoxy-21-chlorocorticosteroids that contain a functionalized ester group at 17α has been prepared and examined to separate their systemic activity from topical antiinflammatory activity. Introduction of the functionalized ester group at 17α was carried out by an acid-catalyzed formation of cyclic ortho esters with 17α,21-hydroxyl groups of corticosteroids and subsequent acid-catalyzed hydrolysis. As for the functional group, chloro, methoxy, acetoxy, cyano, cyclopropyl, or alkoxycarbonyl group was introduced at the terminal carbon atom of the 17α-alkanoate group. The topical antiinflammatory activity and systemic activity of these compounds were examined and found to be signficantly dependent on the functionalities in the 17α-esters. Among these derivatives, a series of 17α-(alkoxycarbonyl)alkanoates (17α-OCO(CH2)(n)COOR) showed an excellent separation of the systemic activity from topical activity. The effects of the number of methylene groups (n) and of the alkyl groups of the ester (R) on either topical or systemic activity of the corticosteroid derivatives were also investigated.
- Ueno,Maruyama,Miyake,Nakao,Nakao,Umezu,Nitta
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p. 2468 - 2473
(2007/10/02)
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- 2-CHLORO-1,1,1-TRIETHOXYETHANE AND ITS USE IN A VERSATILE SYNTHESIS OF SUBSTITUTED, 2-CHLOROMETHYL HETEROCYCLES INCLUDING BENZOTHIAZOLE AND BENZOXAZOLE
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An efficient procedure suitable for large scale preparation of 2-chloro-1,1,1-triethoxyethane and its use in a versatile synthesis of 2-chloromethyl derivatives of an assortment of heterocycles are described.
- Mylari, Banavara L.,Scott, Pamela J.,Zembrowski, William J.
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p. 2921 - 2924
(2007/10/02)
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- Process for preparing chloromethyl thiazoles or oxazoles, and intermediates for use therein
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Chloromethyl group substituted heterocyclic compounds of the formulae STR1 wherein X is O or S; Y together with the two carbons to which Y is attached forms phenyl, pyridyl or pyrimidyl, each of which may be substituted by R; R is one of iodo or trifluoromethylthio or one or two of fluoro, chloro, bromo, (C1 -C4)alkyl, (C1 -C4)alkoxy, (C1 -C4)alkylthio, (C1 -C4)alkylsulfinyl, (C1 -C4)alkylsulfonyl or trifluoromethyl; and R1 is hydrogen or R, are prepared by reacting a bifunctional compound of the formulae STR2 with a 2-chloro-1,1,1-tri(C1 -C6)alkoxyethane. Most of the compounds of formulae I and II are novel. These compounds are intermediates of use in the preparation of compounds having pharmaceutical activity. The 2-chloro-1,1,1-tri(C1 -C6)alkoxyethanes are prepared from the corresponding tri(C1 -C6)alkoxyethanes by chlorination with N-chlorosuccinimide or with chlorine in pyridine and a chlorohydrocarbon cosolvent.
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