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With 1-methyl-pyrrolidin-2-one; ammonia; at 0 - 190℃; for 8h;
0.5 mol (124.7 g) of an 80:20 isomeric mixture consisting of <strong>[50594-82-6]3,4,5-trichlorobenzotrifluoride</strong> and 2,4,5-trichlorobenzotrifluoride and 1.8 mol (178 g) of N-methylpyrrolidone are introduced into an autoclave. The autoclave is cooled to 0C and charged with 4 mol of ammonia (68 g) and heated with vigorous stirring to 190C for 8 hours. After cooling and removal of excess ammonia, the reaction mixture is filtered off from the ammonium chloride produced and the liquid phase is vacuum distilled. The distillation yields 88.3 g of an azeotropic mixture containing 83% 2,6-dichloro-4-trifluoromethylaniline (2,6-DC-pTFMA) and 17% N-methylpyrrolidone. The 99% pure product is precipitated out from the azeotropic mixture by addition of water and, after filtration and drying, 0.317 mol (73 g) of 2,6-dichloro-4-trifluoromethylaniline (yield 79.2% relative to 3,4,5-TCBTF) are obtained. Examples 2 and 3 below are given in order to illustrate the advantage of keeping the conversion of 3,4-DCBTC into 3,4,5-TCBTC at a low level in the chlorination stage, in that if conversion of the 3,4-DCBTC is boosted, the result is not a greater yield of 3,4,5-TCBTC, but instead the formation of isomeric and polychlorinated products which require costly disposal
With 1-methyl-pyrrolidin-2-one; ammonia; at 0 - 190℃; for 8h;
0.5 mol (124.7 g) of <strong>[50594-82-6]3,4,5-trichlorobenzotrifluoride</strong> and 1.8 mol (178 g) of N-methylpyrrolidone are mixed in an autoclave. The autoclave is cooled to 0 C and charged with 4 mol of ammonia (68 g) and heated with vigorous stirring to 190 C for 8 hours. After cooling and removal of excess ammonia, the reaction mixture is filtered off from the ammonium chloride produced and the liquid phase is vacuum distilled. The distillation yields 110.4 g of an azeotropic mixture containing 83% 2,6-dichloro-4-trifluoromethylaniline and 17% N-methylpyrrolidone. The 99% pure product is precipitated out from the azeotropic mixture by addition of water and, after filtration and drying, 0.396 mol (91 g) of 2,6-dichloro-4-trifluoromethylaniline (yield 79.2%) are obtained.
75.69%
With ammonia; In water; at 165℃; under 86258.6 Torr;Product distribution / selectivity;
Example 10-Example 19The unit and operation procedures are same to that of example 7, with results shown in Table 2.
With sodium nitrite;copper(I) chloride; In hydrogenchloride; water;
(b) Preparation of 3,4,5-trichlorobenzotrifluoride 2,6-Dichloro-4-trifluoromethylaniline (3.3 kg) in concentrated hydrochloric acid (25 liters) was stirred for 1 hour and then cooled to -6 C. A solution of sodium nitrite (1.41 kg) in water (3 liters) was added over a period of 4 hours keeping the temperature between -5 and -12. The mixture was then stirred between -5 and 0 until all solid had dissolved (3.5 hours). The mixture was then added in 2 liter portions over a period of 35 minutes to a solution of cuprous chloride (1.5 kg) in concentrated hydrochloric acid with stirring. The dark solution was left to stand for 30 minutes, filtered, and extracted with dichloromethane (1*15 liters, then 2*10 liters). The extracts were washed with water (2*25 liters) dried (MgSO4) and evaporated under reduced pressure to give 3,4,5-trichlorobenzotrifluoride (2.2 kg) with a boiling range of 98- 100/40 Torr.
General procedure: Substituted aniline (5mumol) was dissolved in 5mL of DMF, and sodium hydroxide (10mumol) was added to the solution. The solution was stirred for 10min, and corresponding intermediate phthalonitrile (or isophthalonitrile or terephthalonitrile) (5mumol) was then added. The reaction mixture was stirred at 60°C and monitored by TLC. After completion of the reaction (2h), the mixture was then added to 50mL water and extracted with ethyl acetate (3mL×100mL). The combined extracts were washed with brine, dried (anhydrous magnesium sulfate), and filtered. The filtrate was then evaporated and the crude product was purified via silica gel column chromatography, using a 1:4 (v/v) mixture of ethyl acetate and petroleum ether (boiling point range: 60?90°C) of the eluting solution to obtain the title compound 3; except for 3h, 3i and 3k.
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