623-26-7, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 623-26-7 name is Terephthalonitrile, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
EXAMPLE 3; Hydrogenation; Into a 1-L autoclave equipped with an electromagnetic stirrer, 4 g of Raney nickel catalyst (“NDHT” manufactured by Kawaken Fine Chemicals Co., Ltd.) was charged. Then, 60 g of terephthalonitrile, 60 g of MX and 120 g of methanol were charged into the autoclave and the inner atmosphere thereof was replaced with nitrogen. After introducing 120 g of NH3, the autoclave was heated to 80C. Then, hydrogen gas was introduced into the autoclave to perform the hydrogenation under 8 MPaG at 80C. After initiating the hydrogenation, the reaction liquids were sampled at regular time intervals and analyzed by gas chromatography. After three hours from the initiation, the nitrile conversion reached 97.9 mol%. At this time, the residue of terephthalonitrile was 0.0 mol%, the yield of p-xylylenediamine was 79.0 mol%, and the yield of 4-cyanobenzylamine was 4.3 mol%. After three hours from the initiation, the reaction temperature was raised to 120C to continue the hydrogenation for 1.5 h (overall reaction time = 4.5 h). The results of gas chromatographic analysis showed that the nitrile conversion was 99.99 mol%, the residue of terephthalonitrile was 0.0 mol%, the yield of p-xylylenediamine was 83.9 mol%, and the yield of 4-cyanobenzylamine was 0.015 mol%. Purification of Xylylenediamine After releasing the pressure, MX and methanol were removed from the recovered reaction liquid in a rotary evaporator. By distilling the resultant solution under 0.5 kPa, p-xylylenediamine was obtained as the major distillate. The purity was 99.9% by weight or more and the content of 4-cyanobenzylamine was 0.016% by weight. COMPARATIVE EXAMPLE 3; Hydrogenation; The procedure of Example 3 was repeated except for performing the hydrogenation for 6 h at a constant reaction temperature of 80C. After 6 h of the initiation of hydrogenation, the reaction liquid was analyzed by gas chromatography. The residue of terephthalonitrile was 0.0 mol%, the yield of p-xylylenediamine was 82.2 mol%, and the yield of 4-cyanobenzylamine was 0.4 mol%. Although the hydrogenation was continued longer than in Example 3, a larger amount of the intermediate 4-cyanobenzylamine remained.Purification of Xylylenediamine After releasing the pressure, MX and methanol were removed from the recovered reaction liquid in a rotary evaporator. By distilling the resultant solution under 0.5 kPa, p-xylylenediamine was obtained as the major distillate. The obtained p-xylylenediamine contained 0.4% by weight of 4-cyanobenzylamine. COMPARATIVE EXAMPLE 4; The procedure of Example 3 was repeated except for performing the hydrogenation for 4.5 h at a constant reaction temperature of 120C. The results of gas chromatographic analysis showed that the residue of terephthalonitrile was 0.0 mol%, the yield of p-xylylenediamine was 74.2 mol%, and the yield of 4-cyanobenzylamine was 0.01 mol%.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, Terephthalonitrile, and friends who are interested can also refer to it.
Reference:
Patent; MITSUBISHI GAS CHEMICAL COMPANY, INC.; EP1454895; (2004); A1;,
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts