1,2-dichloro-3-methylbenzene

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 208 mmole concentrated nitric acid and 270 mmole concentrated sulfuric acid were mixed and cooled to ambient temperature. 200 mmole 2,3-dichlorotoluene was added to a reaction flask and was cooled in an ice-water bath. The acid mixture was added slowly with stirring to the dichlorotoluene keeping the dichlorotoluene in the ice-water bath. After all the acid had been added, the mixture in the ice-water bath was stirred for about 10 minutes. A drying tube was attached to the reaction flask and the reaction mixture warmed to ambient temperature. The reaction mixture was heated at 50° C. with stirring for three hours. was cooled in an ice-water bath The acid mixture was added slowly After all the acid had been added A drying tube was attached to the reaction flask the reaction mixture warmed to ambient temperature The reaction mixture was heated at 50° C.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting a dichlorotoluene with carbon tetrachloride in 1,2-dichloroethane in the presence of an aluminum halide to thereby obtain crude dichlorotrichloromethyltoluene; and then

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting a dichlorotoluene with carbon tetrachloride in 1,2-dichloroethane in the presence of an aluminum halide to thereby obtain crude dichlorotrichloromethyltoluene; and then

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting a dichlorotoluene with carbon tetrachloride in 1,2-dichloroethane in the presence of an aluminum halide to thereby obtain crude dichlorotrichloromethyltoluene; and then

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example I was repeated, but this time cobalt (II) acetate tetrahydrate (0.012 moles), sodium bromide (0.05 moles), dichlorotoluene (0.074 moles), acetic acid (100 g) and hydrogen peroxide (70%, 0.68 moles) were used and the reaction was performed at 90° C. for three hours. The final reaction mixture, analysed by HPLC, revealed that 66.0% of the dichlorotoluene had been consumed, yielding products including dichlorobenzaldehyde (15.2% yield) and dichlorobenzoic acid (23.8% yield). The final reaction mixture had been consumed yielding products

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example I was repeated, but this time cobalt (II) acetate tetrahydrate (0.012 moles), sodium bromide (0.05 moles), dichlorotoluene (0.074 moles), acetic acid (100 g) and hydrogen peroxide (70%, 0.68 moles) were used and the reaction was performed at 90° C. for three hours. The final reaction mixture, analysed by HPLC, revealed that 66.0% of the dichlorotoluene had been consumed, yielding products including dichlorobenzaldehyde (15.2% yield) and dichlorobenzoic acid (23.8% yield). The final reaction mixture had been consumed yielding products

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The chlorination of toluene in the presence of catalysts is known to produce the ring-chlorinated isomeric o-, m- and p-monochlorotoluenes in a ratio which varies according to the type of catalyst used and the reaction conditions chosen. Thus, for example, the chlorination of toluene at 50° C. in the presence of FeCl3 as catalyst up to a density of 1.043 g/cm3 (20° C.) leads to a product comprising 19% by weight of toluene, 49% by weight of o-chlorotoluene, 2% by weight of m-chlorotoluene and 25.5% by weight of p-chlorotoluene. Apart from these, 4.5% of dichlorotoluene are additionally formed (Ullmanns Encyl. der techn. Chemie [Ullmann's Encyclopedia of Industrial Chemistry] (1975), Volume 9, page 512). The use of TiCl4, SnCl4, WCl6 or ZrCl4 as catalysts at a chlorination temperature of 10°-30° C. increases the o-chlorotoluene content to 75% by weight (U.S. Pat. No. 3,000,975), while the use of disulfide dichloride and the metal chlorides mentioned or of sulfur and SbCl3 shifts the isomeric ratio in favor of p-chlorotoluene (U.S. Pat. No. 1,946,040). There is no successful instance of obtaining a single isomer by a suitable choice of catalyst or reaction conditions. All these processes therefore require a subsequent separation of the reaction mixture into the pure isomers, which separation is customarily carried out in two stages where, in a first working-up stage, which is expensive in outlay and energy, o-chlorotoluene (boiling point 158.5° C.) is separated as top product by distillation, for example in a bubble cap column having over 200 theoretical plates, from a bottom comprising m- and p-chlorotoluene. Due to the small difference in the boiling points of these isomers (161.2° C. and 161.5° C. respectively), it is no longer possible to separate their mixture by distillation. Pure p-chlorotoluene (melting point 7.6° C.) must therefore be separated in a second step by crystallization from the m-isomer, which has a lower melting point (melting point -48.7° C.). the reaction conditions at 50° C. up to a density of 1.043 g/cm3 (20° C.)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-Dichlorotoluene (8.05 g., 0.05 mol.) dissolved in 150 ml. of carbon tetrachloride containing N-bromosuccinimide (8.9 g., 0.05 mol.) was heated to reflux and irradiated with a 275-watt sunlamp for two hours. The mixture was cooled, filtered and evaporated to give α-bromo-2,3-dichlorotoluene. The α-bromo-2,3-dichlorotoluene (2.4 g., 0.01 mol.) and thiourea (0.38 g., 0.005 mol.) were dissolved in 25 ml. of ethanol and refluxed for about sixteen hours. The mixture was cooled, concentrated, treated with ether, filtered and the filter cake recrystallized from water to give carbamimidothioic acid 2,3-dichlorobenzyl ester, m.p. 238°-243° C. (dec.). was heated to reflux irradiated with a 275-watt sunlamp for two hours The mixture was cooled filtered evaporated