- ON THE REGIOSELECTIVITY OF THE REACTION OF N-METHOXYCARBONYLPYRIDINIUM CHLORIDE WITH GRIGNARD REAGENTS: HIGHLY REGIOSELECTIVE SYNTHESIS OF 2-SUBSTITUTED N-METHOXYCARBONYL-1,2-DIHYDROPYRIDINES.
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Whereas alkyl Grignard reagents undergo 1,2- and 1,4-additions to N-methoxycarbonyl-pyridinium chloride in a variable ratio, alkenyl and alkynyl Grignard reagents do the exclusive 1,2-addition to afford 2-substituted N-methoxycarbonyl-1,2-dihydropyridines in fair to excellent yields.
- Yamaguchi, Ryohei,Nakazono, Yutaka,Kawanisi, Mituyosi
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- PROCESSES FOR PREPARING 4-METHYL-5-NONANONE AND 4-METHYL-5-NONANOL
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The present invention provides a process for preparing 4-methyl-5-nonanone of the following formula (3), the process comprising at least a step of subjecting pentanoic anhydride of the following formula (1) and a 2-pentyl nucleophilic reagent of the following general formula (2), in which M represents Li, MgZ1, or ZnZ1, wherein Z1 represents a halogen atom or a 2-pentyl group, to a nucleophilic substitution reaction to produce 4-methyl-5-nonanone (3), as well as a process for preparing 4-methyl-5-nonanol of the following formula (7), the process comprising at least steps of preparing 4-methyl-5-nonanone and subjecting the obtained 4-methyl-5-nonanone and a reducing agent to a reduction reaction to produce 4-methyl-5-nonanol (7).
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Paragraph 0183-0189
(2020/07/14)
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- Valeric anhydride preparation method
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The present invention discloses a valeric anhydride preparation method comprising the following steps: (a) adding an organic solvent and valeric acid into a reaction vessel, then adding portionwise dicyclohexyl carbodiimide for reaction at the room temperature for 20 to 40 minutes; and (2) removing solid impurities by filtration, recovering the organic solvent by distillation under reduced pressure, after the the organic solvent is completely recovered, heating for distilling under reduced pressure to obtain an object product valeric anhydride. The method uses the valeric acid and the dicyclohexyl carbodiimide for reaction for preparation of the valeric anhydride, the separation process is simple, the obtained valeric anhydride is high in quality, and the valeric anhydride purity reaches 99.3%.
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Paragraph 0019; 0020
(2016/11/17)
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- Exploring functional cyclophellitol analogues as human retaining beta-glucosidase inhibitors
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The natural product, cyclophellitol and its aziridine analogue are potent mechanism-based retaining β-glucosidase inhibitors. In this paper we explore the inhibitory potency of a number of cyclophellitol analogues against the three human retaining β-glucosidases, GBA, GBA2 and GBA3. We demonstrate that N-alkyl cyclophellitol aziridine is at least equally potent in inhibiting the enzymes evaluated as its N-acyl congener, whereas the N-sulfonyl analogue is a considerably weaker inhibitor. Our results complement the literature on the inhibitory potency of cyclophellitol analogues and hold promise for the future design of more effective activity-based retaining glycosidase probes with respect to probe stability in physiological media.
- Li, Kah-Yee,Jiang, Jianbing,Witte, Martin D.,Kallemeijn, Wouter W.,Donker-Koopman, Wilma E.,Boot, Rolf G.,Aerts, Johannes M. F. G.,Code, Jeroen D. C.,Van Der Marel, Gijsbert A.,Overkleeft, Herman S.
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p. 7786 - 7791
(2014/12/10)
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- Synthesis of α-diazoketone by the action of diazoalkanes on butyric anhydride
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Butyric anhydride reacts with diazo-n-alkanes In dry ether at 0°C gave 1-diazo-1-n-alkyl pentanones.
- Chakraborty, Saurabh,Agarwal
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body text
p. 1573 - 1575
(2011/10/31)
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- Kinetics of alcoholysis of valeric anhydride by cyclohexanol in the presence of formic acid
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Kinetics of the reaction proceeding at the industrial process of cyclohexane oxidation are studied by the model reaction of the alcoholysis of valeric anhydride by cyclohexanol in the presence of formic acid.
- Kotel'Nikova,Revkov,Voronina,Perkel
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experimental part
p. 466 - 472
(2009/07/10)
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- Simple preparation of symmetrical carboxylic acid anhydrides by means of Na2CO3/SOCl2
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A convenient and general method for the synthesis of symmetrical carboxylic acid anhydrides using sodium carbonate/thionyl chloride is described. Copyright Taylor & Francis Group, LLC.
- Kazemi,Kiasat,Mombaini
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p. 3219 - 3223
(2008/02/12)
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- Indole derivative and application thereof
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This invention relates to a compound represented by formula (I) or a salt thereof, and a therapeutic agent for osteoporosis, an osteoblast activator, and an osteoclast suppressor comprising the same: wherein X represents a halogen atom; R1 represents a hydrogen atom, substituted or unsubstituted C1-6 alkyl, substituted or unsubstituted C2-6 alkenyl, substituted or unsubstituted C2-6 alkynyl, a substituted or unsubstituted aromatic group, substituted or unsubstituted aralkyl, substituted or unsubstituted acyl, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted C1-6 alkylsulfonyl, or hydroxyl; R2 represents substituted or unsubstituted C1-21 alkyl; R3, R5 and R6, which may be the same or different, each represent a hydrogen atom or a halogen atom; and R4 represents a hydrogen atom or substituted or unsubstituted C1-6 alkyl.
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Page/Page column 9
(2010/11/28)
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- Dabco/SOCl2, mild, and convenient reagent for the preparation of symmetrical carboxylic acid anhydrides
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Various types of carboxylic acids undergo rapid dehydration with 1,4-diazabicyclo[2.2.2]octane, dabco / thionyl chloride, under mild reaction conditions to afford symmetrical acid anhydrides in high isolated yields.
- Kazemi, Foad,Kiasat, Ali Reza
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p. 2287 - 2291
(2007/10/03)
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- A search for quantitative acylation of α-trinositol (1D-myo-inositol 1,2,6-tris(dihydrogen phosphate) pentasodium salt)
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The acylation of α-trinositol is very sensitive to reaction conditions. Competing condensation reactions may give pyrophosphates and cyclic phosphates. Treatment of a tert-ammonium salt corresponding to α-trinositol with carboxylic acid anhydride and DMAP gives a good yield of the expected esters.
- Malmberg, Mats,Rehnberg, Nicola
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p. 459 - 464
(2007/10/03)
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- REACTION OF PHOSPHORUS TRICHLORIDE WITH CARBOXYLIC ACIDS
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The reaction of phosphorus trichloride with a number of monobasic carboxylic acids has been studied and the optimum ratio of reactants for the yield of acid chlorides has been established.Based on analysis and the data from 31P NMR spectroscopy of the phosphorus-containing products from this reaction it is shown that at 40-50 deg C a mixture of P-H acids having a predominant content of pyrophosphorous acid is formed.
- Valitova, L. A.,Popova, E. V.,Ibragimov, Sh. N.,Ivanov, B. E.
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p. 366 - 370
(2007/10/02)
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- Hydroxy protection groups
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The present invention concerns a method for preparing unprotected hydroxy compounds or acylated derivatives thereof by conversion of silyl alkyl-protected hydroxy compounds. The invention also relates to novel intermediates useful in the method and for other purposes.
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- Highly Regioselective α-Addition of Alkynyl and Alkenyl Grignard Reagents to 1-Alkoxycarbonylpyridinium Salts and Its Application to Synthesis of 1-Azabicycloalkanes and (+/-)-Solenopsin A
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Nucleophilic addition of a variety of alkynyl and alkenyl Grignard reagents to 1-methoxycarbonylpyridinium chloride takes place at the α-position in a highly regioselective manner to give 2-substituted 1-methoxycarbonyl-1,2-dihydropyridines exclusively, while, with alkyl Grignard reagents, a lack of the regioselectivity is observed.These results may be explained by the HSAB principle.The high α-regioselectivity is preserved in the cases of 2-substituted pyridines as well, giving 2,6-disubstituted 1,2-dihydropyridines exclusively, which can be transformed stereoselectively into cis- and trans-2,6-dialkylated piperidines.These highly regioselective α-alkynylations of 1-methoxycarbonylpyridinium salts are exploited in synthesis of 1-azabicycloalkanes as well as (+/-)-solenopsin A.
- Yamaguchi, Ryohei,Nakazono, Yutaka,Matsuki, Toshitsugu,Hata, Ei-ichiro,Kawanisi, Mituyosi
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p. 215 - 222
(2007/10/02)
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- Application of the Triphenylphosphine and Diethyl Azodicarboxylate to the Conversion of Carboxylic Acids. Synthesis of Acid Anhydrides
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A new application of the TPP-DEAD reagent has been described.The carboxylic acids undergo self-condensation which takes place during the reaction with betaine 1 and yield acid anhydrides.This synthesis is simple, occurs under very mild conditions and appers to be general.The reaction was monitored by 31P spectroscopy and the mechanism involving the formation of unstable acyloxyphosphonium salts has been discussed.
- Grochowski, Edward,Stepowska, Halszka,Michejda, Cristopher J.
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p. 129 - 134
(2007/10/02)
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- Optical brightening agents of naphthalimide derivatives
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A naphthalimide derivative having the formula STR1 wherein R is an alkyl, or cycloalkyl, an aralkyl, a haloalkyl, an alkoxyalkyl, a hydroxyalkyl, an N,N-dialkylaminoalkyl, an unsubstituted or halogen-, alkyl-, alkoxy- or hydroxy-substituted aryl, or an ammoniumalkyl; X is a group of the formula, STR2 wherein A is STR3 or an unsubstituted or halogen-substituted arylene, or a group of the formula, STR4 wherein R1 is hydrogen, an alkyl, phenyl, a hydroxyalkyl, or an alkoxyalkyl; Y is --CO--, --COO--, --CONR3 -- (where R3 is hydrogen or an alkyl), or --SO2 --; R2 is hydrogen, an alkyl, a cycloalkyl, an aralkyl, a haloalkyl, an alkyl- or aryl-substituted amino-alkyl, an unsubstituted or halogen-, alkyl-, alkoxy-, hydroxy-, amino- or alkylamino-substituted aryl, a group of the formula, STR5 (where R, R1 and Y are as defined above and R4 is a bivalent group), or a group of the formula, (where R5 is direct linkage or a bivalent group; Q+ is a substituted ammonium, a cycloammonium or a hydrazinium; and α- is an anion), Which is useful for optically brightening an organic polymer material.
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