2.4- dichlorophenyl acetate

Organic anion based hydrazinium salts have also been prepared by neutralization of aqueous hydrazine hydrate with 2,4-dichlorophenyl-acetic acid, phenoxyacetic acid, 2,4-dichlorophenoxyacetic acid. 

Preparation by Fries rearrangement of 2,5-dichlorophenyl acetate with aluminium chloride without solvent at 155-165° (36%) [1861]. 

Carboxy-3,5-dichlorophenyl diazo-nium chloride, 31, 97 Catalyst, ammonium acetate, 31, 25, 27 copper chromite, 31, 32 ferric nitrate, hydrated, 31, 53 piperidine, 31, 35 piperidine acetate, 31, 57 Catechol, 33, 74... 

Treatment of the iminoacetate 152 with 4-chlorobenzoyl chloride in the presence of a base gave the desired ethyl 5-(4-chlorophenyl)-l-(2,4-dichlorophenyl)-17/-l,2,4-triazolecarboxylate 153 and the uncyclised ethyl 2-(4-chlorobenz-amido)-2-(2-(2,4-dichlorophenyl)hydrazinyl)acetate 154 in 36% and 6% yield, respectively. The undesired compound 154 was subsequently converted to 1,2,4-triazole 153 in 93% yield by further treatment with pyridine (Equation 47) <2006EJM114>. 

The reaction of 2-mercapto-4-(2, 4 -dichlorophenyl)-5-cyanopyrimidin-6(l//)one 421 (obtained by stirring ethyl cyanoacetate and thiourea with 2,4-dichlorobenzaldehyde in sodium ethylate at room temperature, in 70% yield), with a solution of monochloroacetic acid and />-cholorobenzaldehyde in glacial acetic acid, in the presence of sodium acetate, affords 2-[(/>-chlorophenyl)methylene]-6-cyano-7-(2, 4 -dichlorophenyl)thiazolo[3,2-tf]pyrimidin-3,5-dione 422. Finally, the reaction of compound 422 with hydrazine hydrate converts it into product 423 (Scheme 49) < 1996PS( 116)39>. 

Trace amounts of bromine in sodium diclofenac, sodium (2-[(2, 6-dichlorophenyl)amino] phenyl acetate, have been determined using XRF [82], since the drug substance should not contain more than 100 ppm of organic bromine remaining after the completion of the chemical synthesis. Pellets containing the analyte were compressed over a boric acid support, which yielded stable samples for analysis, and selected XRF spectra obtained in this study are shown in Fig. 7.19. It was found that samples from the Far East contained over 4000 ppm of organic bromine, various samples from Europe contained about 500 ppm, while samples from an Italian source contained less than 10 ppm of organic bromine. 

Procedure 3 Resolution of (+)-4-Cyano-4-(3, 4 -dichlorophenyl)cyclohex-l-enyl Acetate (8)... 

Dichlorophenol, see 2,4-Dichlorophenol 3-(3,4-Dichlorophenol)-l,l-dimethylnrea, see Dinron Dichlorophenoxyacetic acid, see 2,4-D (2.4-Dichlorophenoxy)acetic acid, see 2,4-D 3-(3,4-Dichlorophenyl)-l,l-dimethylnrea, see Dinron A -(3,4-Dichlorophenyl)-lV,lV-dimethylnrea, see Dinron Dichlorophos, see Dichlorvos a.p-Dichloropropane, see 1,2-Dichloropropane ds-l,3-Dichloropropene, see cis-l,3-Dichloropropylene frans-l,3-Dichloropropene, see ans-l,3-Dichloro-... 

To a solution of 298 gm (8 equivalents) of hydrazine in ether is slowly added with stirring and cooIing215 gm (1.15 moles) of 3,4-dichlorophenyl isocyanate in 2 liters of ether while keeping the temperature at 20°C. After the addition the ether layer is decanted from the oily layer. On dilution of the oily layer with water is obtained 237.5 gm of a solid. Recrystallization from ethanol and filtration to remove the insoluble l,6-bis(3,4-dichlorophenyl)biurea afford 108.6 gm of a solid, m.p. 175°-177°C. An additional recrystallization from 700 ml of ethyl acetate affords 77.3 gm (30%), m.p. 173°175°C, ir 3.00, 3.10 p. (NH), 5.90 jji (C=0). 

Silanetriols eluded all attempts at their isolation until a few years ago when Tyler (88) prepared phenylsilanetriol from phenyltrimethoxysilane and dilute acetic acid at about 10°. More recently Takiguchi (82) obtained this substance from phenyltrichloiosilane in the presence of aniline. Andrianov, Zhdanov and Morganova (7) obtained dichloro-phenylsilanetriol by hydrolyzing the triacetoxysilane. The interesting tetrol, bis-(dichlorophenyl)-disiloxanetetrol, was similarly obtained from bis-(dichlorophenyl)-tetraacetoxydisiloxane. 

Dichlorophenyl)-l-piperazinopropionitrile (20.0 g), acetic anhydride (100 ml), anhydrous sodium sulfate (12.0 g) and a 50% solution of Ni-Raney (6 ml) are hydrogenated at 60.0 pounds per inch at 60°C in a Parr apparatus. After about half an absorption of hydrogen is complete. The reaction mixture is cooled, the is filtered and the solution is concentrated to small volume in a rotating evaporator. The residue is treated with NaOH solution and extracted several times CH2CI2. The organic layer is washed, dried and evaporated. The residue is crystallized from ethyl acetate. 14.0 g of the l-(3-acetylaminopropyl)-4-(2,5-dichlorophenyl)piperazine are obtained, melting point 114°C. 

A stirred and cooled (0°C) solution of l-(2,4-diaminophenyl)-l-ethanone in a concentrated hydrochloric acid solution, water and acetic acid was diazotated with a solution of sodium nitrite in water. After stirring at 0°C, the whole was poured onto a solution of copper (I) chloride in a concentrated hydrochloric acid solution while stirring. The mixture was heated at 60°C. After cooling to room temperature, the product was extracted twice with 2,2 -oxybispropane. The combined extracts were washed successively with water, a diluted sodium hydroxide solution and again twice with water, dried, filtered and evaporated, yielding l-(2,4-dichlorophenyl)-l-ethanone. 

A solution of 2.57 g of l-(2, 4 -dichlorophenyl)-2-(N-imidazolyl)ethanol in 10 ml of hexamethylphosphoramide was dropped at 25°C into a suspension of 0.52 g of sodium hydride (50% in oil) in 5 ml of hexamethylphosphoramide. When hydrogen emission was over, the salification was completed by heating for 1 hour at 50°C. After cooling to 25°C, 2.58 g of l-chloromethyl-4-phenylthiobenzene were added. The temperature was raised to 50°C and maintained at that temperature for 12 hours. At the end of the reaction, the mixture was poured into 200 ml of water, the product was extracted with diethyl ether, the solvent was evaporated off and the residue was purified twice on a silica gel column, using ethyl acetate as eluant and testing the various fractions by TLC. The solvent was evaporated off the middle fractions... 

The reaction mixture was then cooled and poured into 2 L of ice/water. The resulting mixture was acidified with 10% HCI and extracted with ethyl acetate (3 times 1 L). The combined ethyl acetate extract was extracted with 1 N NH4OH (3 times 1 L) and the combined aqueous basic extract washed with ethyl acetate (2 L), cooled to 0° to 5°C, acidified slowly to a pH below 1.0 with concentrated HCI and extracted with ethyl acetate (4 times 2 L). The combined ethyl acetate extract was dried (MgS04) and evaporated under vacuum to a light yellow oil slightly contaminated with diethyl succinate (477 g, 80% yield). An analytical sample of 3-ethoxycarbonyl-4-(3,4-dichlorophenyl)-4-phenylbut-3-enoic acid was crystallized from petroleum ether (melting point 128°-130°C). 

A solution of 4-(3,4-dichlorophenyl)-4-phenylbut-3-enoic acid (223 g, 0.73 mole) in ethyl acetate (2 L) was hydrogenated over 8 g of 5% Pd/C catalyst at atmospheric pressure and room temperature until hydrogen uptake ceased (24 h). The catalyst was separated by filtration and the filtrate evaporated under vacuum to a light brown oil containing traces of solvent (ca. 100% yield). An analytical sample of the 4-(3,4-dichlorophenyl)-4-phenylbutanoic acid was crystallized from hexane (melting point 118°-120°C). 

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