- A new method for preparing intermediates of Fludioxonil (by machine translation)
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The invention relates to the field of organic synthesis, in particular to a new method for preparing intermediates of Fludioxonil. Difluoro [...] formaldehyde intermediate the synthesis method of the cyclization, chlorinated, fluorine exchange, hydrolysis and the like steps to synthesize. The process is complicated, the unit step more, harsh requirements on equipment, and the yield is low, to the detriment of the industrial production. The invention relates to O-vanillin as the starting material, the preparation of 2, 3 - dihydroxy benzaldehyde, with difluorodichloromethane reaction, in the presence of a, cyclization to obtain important [...] formaldehyde intermediate, not only the process is greatly improved, and the yield is high, waste water is less, there are better application value. (by machine translation)
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Paragraph 0023; 0026-0031
(2018/07/07)
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- Synthetic method of 2,2-dichloro-1,3-benzodioxole-4-formaldehyde
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The invention provides a synthetic method of 2,2-dichloro-1,3-benzodioxole-4-formaldehyde. The synthetic method comprises the following steps of: adding 3-methoxyl-2-hydroxybenzaldehyde and alkali into a protonic solvent, then dropwise adding hydrogen peroxide, and performing hydrolysis reaction; after the complete reaction, performing the after-treatment to obtain 2,3-dihydroxy benzaldehyde; adding an aqueous solution of the 2,3-dihydroxy benzaldehyde and alkali into the protonic solvent, and then adding dichlorodifluoromethane to perform the reaction; and after the complete reaction, performing the after-treatment to obtain the 2,2-dichloro-1,3-benzodioxole-4-formaldehyde. According to the synthetic method, the target product can be obtained from an initial raw material 3-methoxyl-2-hydroxybenzaldehyde by virtue of two-step chemical reaction. The reaction method is moderate in reaction conditions, simple in steps, low in cost, environment-friendly, high in yield, capable of facilitating the industrialized mass production, and capable of setting a foundation for the subsequent successful synthesis of fludioxonil, so that the synthetic method has good application prospect and market potential.
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Paragraph 0057-0059
(2017/07/14)
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- A homologous series of O- and N-functionalized 2,2-difluoro-1,3-benzodioxoles: An exercise in organometallic methodology
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The conversion of 2,2-difluoro-1,3-benzodioxole, an exceptionally acidic arene, via a 4-lithiated intermediate into more than three dozen new derivatives was conceived as a case study. The lithiated species was trapped by C0-electrophiles (4-toluenesulfonyl azide, fluorodimethoxyborane, iodine), C1-electrophiles (carbon dioxide, N,N-dimethylformamide, formaldehyde, dimethyl sulfate), C2-electrophiles (oxalic acid diesters, oxirane), C3-electrophiles (oxetane), and higher alkyl iodides. The resulting carboxylic acid 1a may be treated with organolithium compounds to afford ketones (e.g. 10) and the aldehyde 9 can be condensed with nitromethane or acetic anhydride under basic conditions. If not oxidized with chromium trioxide to the corresponding carboxylic acids, the alcohols 2b, 2c, and 2d can be transformed into the corresponding bromides (12) or sulfonates (13). Their condensation with nitrogen-containing C0-nucleophiles (hydroxylamine, sodium azide, potassium phthalimide), C1-nucleophiles (potassium cyanide), and C2-nucleophiles (aceto-nitrile) opens a convenient access to the amines 3. Other reactions gave, despite a proven track record in other areas, only moderate yields. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Schlosser, Manfred,Gorecka, Joanna,Castagnetti, Eva
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p. 452 - 462
(2007/10/03)
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- Process for the preparation of 2,2-difluorobenzo[1.3]dioxolecarbaldehydes
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2,2-Difluorobenzo[1.3]dioxole-carbaldehydes are prepared in a particularly advantageous manner if methylbenzo[1.3]dioxoles are chlorinated, the resulting dichloromethyl-2,2-dichlorobenzo[1.3]dioxole is fluorinated with hydrogen fluoride and the dichloromethyl-2,2-difluorobenzo[1.3]dioxole obtained by this procedure is reacted with a carboxylic acid.
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- 2,2-difluorobenzo (1,3)-dioxole-carbaldehydes and new intermediate products
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According to the invention, a new process has been found for the preparation of 2,2-difluoro-benzo[1,3]-dioxole-carbaldehydes of the formula (I) STR1 in which benzo[1,3]dioxole-carbaldehydes are chlorinated, the 2,2-dichloro-dichloromethylbenzo[1,3]dioxoles formed, which are likewise new, are partly fluorinated to give the 2,2-difluoro-dichloromethyl-benzo[1,3]dioxoles, which are likewise new, and these are then reacted with urotropin to give the desired compounds.
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- Circulation-active dioxyalkylenearyl-dihydropyridines
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Circulation-active dihydropyridines of the formula STR1 in which R1 is H, CN, NO2 or --COOR7, R7 is H, alkyl or various other radicals, R2 and R4 each independently is alkyl or other radicals, R3 is H or optionally substituted alkyl, and R5 completes a keto or ester group, and physiologically acceptable salts thereof. Also the aldehyde intermediate therefor of the formula STR2
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- Process for the preparation of substituted difluorobenzo-1,3-dioxoles
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The reaction of 2,2-difluorobenzo-1,3-dioxole with (a) an alkali metal or an alkali metal compound and then (b) a compound R1 -Z1 l in which Z1 is a leaving group, or with an aldehyde produces compounds of formula I STR1 wherein R1 l is --OH, --SH, --CHO, --CN, --COOH, --B(OH)2, --COX, with X being Cl or Br, or is --COOR2, --SiR32 or --B(OR2)2, with R2 being a C1 -C12 alcohol moiety without the hydroxy group, wherein R1 is further --Cn H2n COOR2, with n being an integer from 1 to 4, or linear or branched C1 -C12 hydroxyalkyl which is unsubstituted or is substituted by --F, --CN, C1 -C6 alkoxy, phenyl, fluorophenyl, C1 -C4 alkoxy-phenyl, C1 -C4 alkylthio-phenyl, C1 -C4 alkyl-phenyl, C1 -C4 fluoroalkyl-phenyl, nitrophenyl or by cyanophenyl, or wherein R1 is a benzyl alcohol which is unsubstituted or is substituted by F, C1 -C4 alkoxy, C1 -C4 alkylthio, C1 -C4 alkyl, C1 -C4 fluoroalkyl, nitro or by cyano, or is C1 -C12 acyl, or wherein R 1 is a radical of formula II STR2 wherein R5 is --CN, --CF3, --COOR2, --CO--NHR2 or --CONR22, R3 and R4 are a direct bond or each is H, or R3 is H and R4 independently has the meanings of R5, or R3 and R4 together are --CH2 --NR6 --CH2 --, --CH2 --NR6 --CO-- or --CO--NR6 --CO-- wherein R6 is the radical of a removable protecting group, or wherein further R1 is a radical of formula III STR3 Insecticides or fungicides can be prepared from the compounds of formula I. 3-(2,2-difluorobenzodioxol-4-yl)-4-cyanopyrrole can be prepared by reacting 4-metallo-2,2-difluorobenzodioxole (III) with an unsaturated nitrile and then with a sulfonylmethyl isocyanide in a one-pot process. The compounds III are novel intermediates.
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- Circulation-active dioxyalkylenearyl-dihydropyridines
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Circulation-active dihydropyridines of the formula STR1 in which R1 is H, CN, NO2 or --COOR7, R7 is H, alkyl or various other radicals, R2 and R4 each independently is alkyl or other radicals, R3 is H or optionally substituted alkyl, R5 completes a keto or ester group, and R6 is a direct bond or --CF2 -- or --CHF--, and physiologically acceptable salts thereof.
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