- A process for preparing 1-methyl propyl formic acid method
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The invention discloses a method for preparing 1-methyl cyclopropane carboxylic acid and belongs to the fields of fine chemical engineering and medical intermediates. The method comprises the following steps: by taking methacrylic acid (ester or salt), or methacrylonitrile or methacrylamide as a raw material, carrying out a cyclopropanation reaction with trihalide in the presence of an alkali to generate 2,2-geminal halide (III); carrying out a reaction between the 2,2-geminal halide (III) and metallic sodium to remove halogen atoms on the ring so as to generate methyl cyclopropionate or methyl cyclopropaneacetonitrile or methyl cyclopropylamide (II); acidifying the methyl cyclopropanecarboxylate, thereby obtaining 1-methyl cyclopropane carboxylic acid (I); and performing basic hydrolysis on methyl cyclopropaneacetonitrile or methyl cyclopropylamide, and acidifying to obtain 1-methyl cyclopropane carboxylic acid (I). The method disclosed by the invention is readily available in raw materials, mild in reaction conditions, convenient to operate, low in cost and high in purity of the obtained product and is a feasible preparation method.
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- β-Arylation of carboxamides via iron-catalyzed C(sp3)-H bond activation
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A 2,2-disubstituted propionamide bearing an 8-aminoquinolinyl group as the amide moiety can be arylated at the β-methyl position with an organozinc reagent in the presence of an organic oxidant, a catalytic amount of an iron salt, and a biphosphine ligand at 50 C. Various features of selectivity and reactivity suggest the formation of an organometallic intermediate via rate-determining C-H bond cleavage rather than a free-radical-type reaction pathway.
- Shang, Rui,Ilies, Laurean,Matsumoto, Arimasa,Nakamura, Eiichi
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supporting information
p. 6030 - 6032,3
(2013/05/22)
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- Pd(II)-catalyzed enantioselective C-H activation of cyclopropanes
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Systematic ligand development has led to the identification of novel mono-N-protected amino acid ligands for Pd(II)-catalyzed enantioselective C-H activation of cyclopropanes. A diverse range of organoboron reagents can be used as coupling partners, and the reaction proceeds under mild conditions. These results provide a new retrosynthetic disconnection for the construction of enantioenriched cis-substituted cyclopropanecarboxylic acids.
- Wasa, Masayuki,Engle, Keary M.,Lin, David W.,Yoo, Eun Jeong,Yu, Jin-Quan
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supporting information; experimental part
p. 19598 - 19601
(2012/01/17)
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- PYRAZOLE-ISOQUINOLINE UREA DERIVATIVES AS P38 KINASE INHIBITORS
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The present invention provides kinase inhibitors of Formula (I) wherein R1, R2, and X are as described herein, or a pharmaceutically acceptable salt thereof.
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Page/Page column 21
(2008/06/13)
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- Process for the preparation of alkyl 1-methylcyclopropanecarboxylate
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Disclosed is a 4-step process for the preparation of alkyl esters of 1-methylcyclopropanecarboxylic acid which comprises the steps of (1) converting γ-butyrolactone to α-methyl-γ-butyrolactone; (2) converting the α-methyl-γ-butyrolactone from step (1) to an alkyl 4-halo-2-methylbutyrate; (3) producing a xylene solution of the alkyl 4-halo-2-methylbutyrate; and (4) contacting the xylene solution of an alkyl 4-halo-2-methylbutyrate from step (3) with an alkali metal alkoxide under conditions of temperature and pressure which causes vaporization of (i) an alkanol as it is formed and (ii) an alkyl 1-methylcyclopropanecarboxylate as it is formed from the alkyl 4-halo-2-methylbutyrate. Also disclosed are processes whereby the alkyl 1-methylcyclopropanecarboxylate, prepared as described above, is converted to 1-methylcyclopropylamine.
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- Synthesis and spectral properties of cyclopropyl-substituted phosphaalkenes
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Cyclopropanecarboxylic acid chlorides 5a-d react with tris(trimethylsilyl)phosphane 6 in benzene at -2 deg C to form cyclopropylcarbonyl-bis(trimethylsilyl)phosphanes 7.These products undergo silylic rearrangement at 25 deg C to yield phosphoalkenes 8.Compounds 8a,b,d are formed as mixtures of Z- and E-isomers where the latter predominante.In the case of 8c, the Z-isomer is formed exclusively. - Key words: phosphaalkenes, cyclopropyl-substituted, E/Z-isomerism.
- Kostitsyn, A. B.,Ruzek, H.,Heydt, H.,Regitz, M.,Nefedov, O. M.
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p. 635 - 640
(2007/10/02)
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- Kinetics of Cyclopropyl Radical Reactions. 2. Studies on the Inversion of Cyclopropyl and 1-Methylcyclopropyl Radicals and on the Kinetics of Some Addition and Abstraction Reactions of 1-Methylcyclopropyl and 1-Methoxycyclopropyl Radicals
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Laser flash photolytic studies have shown that the 1-methylcyclopropyl radical has a reactivity similar to that of the cyclopropyl radical toward styrene, β-methylstyrene, 1,4-cyclohexadiene, CCl3Br, and n-Bu3SnH but that it is more reactive toward CCl4.Chemical trapping with CCl3Br of these two radicals stereospecifically labeled with deuterium yields rate constants for their inversion at 71 deg C of (2.1 +/- 0.8) * 1011 s-1 for c-C3H4.CH3 and ca. 1012 s-1 for c-C3H5..EPR spectra of 13C-labeled radicals confirm that they are nonplanar: a13Cα = 98 and 95.9 G for c-C3H4.CH3 and c-C3H5., respectively.The similar magnitudes of these splittings implies that there is also a similar degree of deviation from planarity.The barrier to inversion is probably ca. 3 kcal/mol for both radicals but the c-C3H5. inverts more rapidly possibly because of hydrogen tunneling. 1-Methoxycyclopropyl is less reactive toward styrene and 1,4-cyclohexadiene than the other two radicals.The EPR spectrum of this radical could not be obtained.
- Johnston, Linda J.,Ingold, K. U.
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p. 2343 - 2348
(2007/10/02)
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- Generation and Reactions of Lithiated tert-Butyl and 2,6-Di(tert-butyl)-4-methylphenyl Cyclopropanecarboxylates
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tert-Butyl and 2,6-di(tert-butyl)-4-methylphenyl (BHT) cyclopropanecarboxylates (4, 6, 24, 25) are lithiated with LiN(i-Pr)2 and t-BuLi, respectively.Reactions with alkyl halides, aldehydes, acyl chlorides, and heteroelectrophiles give α-substituted BHT esters which can be cleaved (t-BuOK/H2O/THF) to the corresponding carboxylic acids or reduced (LiAlH4/THF) to the cyclopropanemethanols.
- Haener, Robert,Maetzke, Thomas,Seebach, Dieter
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p. 1655 - 1665
(2007/10/02)
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- Dimerization of Cyclopropanecarboxylic Acid Dianion and Thermal Decarboxylative Rearrangement of the Dimer to 2-Cyclopropyl-4,5-dihydrofuran
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The dianion of cyclopropanecarboxylic acid (2) reacted with alkyl halides and deuterated water at temperatures below 0 deg C; however, self-condensation to the β-keto acid 3 was the only observed product at elevated temperatures.This observation contrasts the self-condensation of the ethyl ester where a trimeric diester alcohol is the product.Attempted mixed condensations of the dianion 2 and carboxylic acids without acidic α-protons did not proceed as well, 3 being the major product.Thermal decarboxylation of 3 did not yield the expected dicyclopropyl ketone; rather , a facile rearrangement in a sealed tube at 120 deg C occured, giving rise to 2-cyclopropyl-4,5-dihydrofuran.This "vinyl-cyclopropyl" type rearrangement does not occur through dicyclopropyl ketone or its enolate.
- Jahngen, Edwin G. E.,Phillips, Douglas,Kobelski, Robert J.,Demko, Donald M.
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p. 2472 - 2476
(2007/10/02)
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