- N-alkyl-cyanopyrazole synthetic method
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The invention discloses an N-alkyl-cyanopyrazole synthetic method which comprises the following step of by taking 1-alkyl-1H-pyrazole formaldehyde or a derivative thereof, ammonia water, sodium bromate and acetic acid as raw materials and water as a reaction solvent to obtain N-alkyl-cyanopyrazole . The synthetic method provided by the invention is simple in technology without using extremely toxic substances, convenient in synthesis, high in yield, convenient in purification of an obtained product and beneficial to large-scale industrial production.
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Paragraph 0017
(2018/11/22)
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- PROCESS OF PREPARATION OF AZIMSULFURON
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The present disclosure provides process for preparation of azimsulfuron or its salts, isomers, and other derivatives thereof. The process involves treating a compound of formula I, with aqueous acetic acid or formic acid and chlorine gas or sodium hypochlorite in presence of hydrochloric acid in chlorinated solvents such as dichloromethane, 1,2-dichloroethane or with aqueous acetic acid and N-chlorosuccinimide or hydrogen peroxide in presence of hydrochloric acid in aqueous cyclic ether such as tetrahydrofuran, 1,4-dioxane to obtain 1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonyl chloride; converting the sulfonyl chloride to a sulfonamide and treating the sulfonamide with a phenyl(4,6-dimethoxypyrimidin-2-yl) carbamate to obtain azimsulfuron or its salts, isomers, and other derivatives thereof.
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Paragraph 0237
(2015/04/28)
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- SUBSTITUTUED PYRAZOLE COMPOUNDS AND PROCESS FOR PREPARATION THEREOF.
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The present disclosure provides a compound of formula I, its derivatives, salts, stereo-isomers, or regio-isomers thereof, useful as intermediates in preparation of sulfonamide or sulfonyl urea growth regulators or herbicides. Formula I The present disclosure further provides a process for preparing compound of formula I, its derivatives, salts, stereo-isomers, or regio-isomers thereof.
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Page/Page column 143
(2014/01/17)
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- PROCESS OF PREPARATION OF AZIMSULFURON
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The present disclosure provides process for preparation of azimsulfuron or its salts, isomers, and other derivatives thereof. The process involves treating a compound of formula I, (Formula I should be inserted here.) with aqueous acetic acid or formic acid and chlorine gas or sodium hypochlorite in presence of hydrochloric acid in chlorinated solvents such as dichloromethane, 1,2-dichloroethane or with aqueous acetic acid and N-chlorosuccinimide or hydrogen peroxide in presence of hydrochloric acid in aqueous cyclic ether such as tetrahydrofuran, 1,4-dioxane to obtain 1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonyl chloride; converting the sulfonyl chloride to a sulfonamide and treating the sulfonamide with a phenyl(4,6-dimethoxypyrimidin-2-yl) carbamate to obtain azimsulfuron or its salts, isomers, and other derivatives thereof.
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Page/Page column 43; 44
(2014/01/17)
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- SUBSTITUTED TETRAZOLE COMPOUNDS AND PROCESS THEREOF
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The present disclosure provides a compound of formula I, its derivatives, salts, stereo-isomers, or regio-isomers thereof, useful as intermediates in preparation of sulfonamide or sulfonyl urea growth regulators or herbicides. Formula I The present disclosure further provides a process for preparing compound of formula I, its derivatives, salts, stereo-isomers, or regio-isomers thereof.
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Page/Page column 133
(2014/01/17)
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- Synthesis, structure, and properties of pyrazole-4-carbaldehyde oximes
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1-Alkyl-1H-pyrazole-4-carbaldehyde oximes reacted with acetic anhydride to give the corresponding nitriles, which is typical for anti isomers of aldoximes. The anti configuration of 5-methyl-1-propyl-1H-pyrazole-4-carbaldehyde oxime in crystal was unambig
- Attaryan,Sahakyan,Tamazyan,Ayvazyan,Asratyan
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p. 1720 - 1723
(2013/02/22)
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- Anodic Cyanation of 1-Methylpyrazole
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The electrooxidation of 1-methylpyrazole in methanol containing sodium cyanide produced 1-methylpyrazole-4-carbonitrile 2 and -5-carbonitrile 3 in yields of 23 and 8percent, respectively (2e-oxidation products), together with 4-methoxy-1-methylpyrazole-5-carbonitrile 4 (4e-oxidation product, 4percent).
- Yoshida, Kunihisa,Toyo-oka, Yoshimasa,Takeda, Kazusada
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p. 701 - 702
(2007/10/02)
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- Cyanoacetaldehyde - New Synthetic Applications of an Old Compound Syntheses with Nitriles, XCI
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Various reactions of cyanoacetaldehyde (1), freshly prepared by ozonization of (E)-1,4-dicyano-2-butene or allylcyanide, are described.Thus, conversion of 1 with anilines gave β-phenylaminoacrylonitriles 2a-e.Reaction of 1 with hydrazines led to the corresponding hydrazones 3a-e, which could be cyclized under alkaline conditions to 5-aminopyrazoles 4a-d.An aldol-type condensation product 5a could be obtained by reaction of 1 with sodiumphenoxide.Treatment of 1 with dimethylformamide-dimethylacetal led to the formation of (E)-3-dimethylamino-2-formylpropenenitrile (6), a very useful synthon in synthetic chemistry.For the determination of the structure of 6 the method of steady state diffferential NOEs was used.Reaction of 6 with hydrazines gave 1-substituted-4-cyanopyrazoles 7a-k. Keywords.Cyanoacetaldehyde; Hydrazones; Cyanopyrazoles; Aminopyrazoles.
- Jachak, Madhukar,Kriessmann, Ulrike,Mittelbach, Martin,Junek, Hans
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p. 199 - 208
(2007/10/02)
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- Synthesis of 5-Chloropyrazoles by Chlorodiazoniation with Sulfur Dioxide
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A facile synthesis of 5-chloropyrazoles 4a-e from 5-aminopyrazoles 2a-e via diazotization followed by chlorodediazoniation is described.A new application of sulfur dioxide as a catalyst was demonstrated to be the best for the chlorodediazoniation of diazonium chlorides 3a-e.
- Yamamoto, Susumu,Morimoto, Katsushi,Sato, Toshiaki
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p. 1545 - 1547
(2007/10/02)
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- 1,3-Dipolar Cycloadditions, 93. - The Astounding Reaction of Dimethyl 2,3-Dicyanofumarate with Diazomethane
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The reaction with excess of diazomethane furnished methyl 4-cyano-1-methylpyrazole-5- and -3-carboxylate (2 and 3) as well as the three N-methyl-1,2,3-triazolecarboxylic esters 4-6.A mechanistic study revealed a poly-step sequence.The initial formation of the pyrazoline 8 proceeded normal.Base catalysis effected an equilibration of trans- and cis-2-pyrazoline, 8(*)12, followed by a fragmentation into methyl 4-cyano-3-pyrazolecarboxylate (26) and methyl cyanoformate (32); a 4H-pyrazole is supposed to be the key intermediate.The final products mentioned above emerged from further reaction of 26 and 32 with diazomethane.
- Huisgen, Rolf,Mitra, Abhijit,Moran, Joaquin Rodriguez
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p. 159 - 170
(2007/10/02)
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- THE ASTOUNDING REACTION OF DIAZOMETHANE WITH DIMETHYL 2,3-DICYANOFUMARATE
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The title reaction afforded the pyrazole derivatives 3 and 4 as well as the N-methyl-1,2,3-triazolecarboxylic esters 5 - 7.The poly-step sequence was clarified; the key intermediates are the 1-pyrazoline 18, the 2-pyrazoline 2, the 4H-pyrazole 12, the pyrazole 22, and methyl cyanoformate.
- Huisgen, Rolf,Mitra, Abhijit,Moran, Joaquin Rodriguez
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p. 2429 - 2436
(2007/10/02)
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