1193-21-1

Yellow Solid

The synthesis of 4,6-Dichloropyrimidine is as follows:Dissolve 105.5g of 4,6-diaminopyrimidine in 660.0g of 31% hydrochloric acid and pour into a 2000ml bottle to cool to -5 ° C and dropwise add 500.3g of 33% sodium nitrite. After 2 hours of reaction, HPLC detects 4,6-diamino Pyrimidine is less than 0.5%. 42.8 g of cuprous chloride and 214.0 g of 31% hydrochloric acid are prepared in a 2000 ml bottle. The diazonium salt mother liquor is added dropwise to the bottle. After the dropwise reaction, the reaction is performed at 45 ° C for 2 hours. .Extract with 400g of recovered trichloroethane (200x2 times less than new ones), combine the organic layers for distillation, control the water flush pump 5KPa, temperature 40-140 , collect 404.2g of solvent in the early 40-90 , 90-140 in the later The product was collected at a temperature of 14 ° C to obtain 146.9 g of 4,6-dichloropyrimidine. The yield was 86.4% (based on formazan hydrochloride) and the purity was 99.4%.

[1] Patent: CN108395409, 2018, A. Location in patent: Paragraph 0039-0041; 0044
[2] Patent: CN105439963, 2016, A. Location in patent: Paragraph 0011
[3] Patent: CN108341784, 2018, A. Location in patent: Paragraph 0027; 0028; 0029; 0031-0033; 0039; 0040
[4] Patent: CN105732514, 2016, A. Location in patent: Paragraph 0027; 0028
[5] Patent: CN108178749, 2018, A. Location in patent: Paragraph 0027; 0028; 0030; 0032; 0034; 0036; 0038; 0040