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It was only after some unsuccessful efforts thai we succeeded in 

 carrying out the nitration of ^-chlorotoluene with nitric acid, in that 

 sense thai everything was jus! nitrated, without formation of any 

 dinitro-products. Mr. van den Arend could ascertain this by deter- 

 mining the s|>ocilic gravities. As in the case of pure toluene il was 

 again found practical, in order to avoid the formation of higher 

 products of nitration, to add the nitric acid to the p-chlorotoluene 

 and not reversedly. 



10 grams of »-chlorotoluene wore cooled to . At that temperature 

 it solidities to large leaf-like crystals; at the moment of crystallisation 

 setting- in, nitric acid (D. 1.4.S) was added, drop by drop, with 

 thorough shaking. After lec of acid had been added all the crystals 

 had already fused. The liquid turns very dark and consists at firs! 

 of two layers. After further addition of acid, the temperature being 

 kept at 0° the colour turns pale yellow and the liquid becomes homo- 

 geneous. When this point was reached the further addition of acid 

 was stopped and after a few moments the liquid was poured into 

 water. In all, four times the weight of nitric acid was w^ed. The 

 pale yellow oil which collected at the bottom was agitated repeatedly 

 with water until no further acid reaction was noticed, and then 

 dried over sodium sulphate. The following day, the nitration product 

 was distilled twice in vacuo when a slight, black residue was left 

 behind. The yield of purified product was 12 grams. It had an initial 

 solidifying point of -f- 10. 2 and an end solidifying point of— 8 .0. 

 From the first figure it follows thai the nitration product musl 

 contain 58° „ of CH S ,C1,N0 S = 1, 4, 3, whilst the figure for the end 

 point, which coincides with the eutectic point, shows that the mixture 

 contains no other substances besides these two. This was also proved 

 by the sp. gr. which was found to be L.2481 for an artificial mixture 

 of thi^ composition, whilst the nitration mixture possessed the same 

 sp. gr. Mr. De Leeuw who also nitrated ^-chlorotoluene in the manner 

 described, found the initial solidifying point of his product -f- 10 .'.», 

 the end point 8. 3. This initial point corresponds with 58.8% 1.2.4. 



Mr. van dkn Arend also mixed an artificial mixture of both isomers 

 containing 58°/ 1.2.4 and 42% 1-3.4 with the nitration product in 

 about equal quantities; the mixture so obtained solidified at -f- 10°. 3. 



It may, therefore, be taken as proved thai the nitration product 

 has the above composition. A chlorine determination according to 

 Carius gave 20.3° „ (calculated 20.7 " ,). 



Two nitrations were carried out al -j- 30 3 in the manner de- 

 scribed, using nitric acid (I). 1.45) which both yielded a product 

 the sp. gr. of which was much too high. It appeared that at this 



