Acetic Acid → 1,4-Dinitro-1H-imidazole

After 20 g of 4-nitroimidazole was put in a flask, 36.4 mL of acetic acid was added thereto and while the temperature of the reaction solution was kept below 20° C., 14.6 mL of 97 mass % nitric acid was added dropwise thereto. After the dropwise addition of nitric acid was completed, 36.4 mL of acetic anhydride was added dropwise thereto and after the temperature of the reaction solution elevated to 25° C., the resultant mixture was allowed to react for 3 hours. After the reaction ended, the reaction solution was added into 100 g of iced water. Extraction with 100 mL of methylene chloride was performed three times and this organic layer was washed twice with 100 mL of a saturated sodium hydrogen carbonate aqueous solution. The organic layer was separated and 30 g of magnesium sulfate was added thereto for dehydration to obtain 1,4-dinitroimidazole as a dichloromethane solution. Subsequently, the solvent was evaporated with an evaporator to such an extent that the solution was not dried to solid and then 300 mL of chlorobenzene was added thereto, and the solution was heated to 125° C. and allowed to react for 24 hours so as to perform conversion to 2,4-dinitroimidazole. After the reaction ended, the deposited solid was filtered to obtain 25.3 g of 2,4-dinitroimidazole as a solid wetted with chlorobenzene (wetted with 10 mass % of chlorobenzene, yield 82.3%). This was identified to be 2,4-dinitroimidazole by

1. customwas kept below 20° C.
2. customelevated to 25° C.
3. customto react for 3 hours
4. extractionExtraction with 100 mL of methylene chloride
5. washthis organic layer was washed twice with 100 mL of a saturated sodium hydrogen carbonate aqueous solution
6. customThe organic layer was separated
7. addition30 g of magnesium sulfate was added

ORD record

ord-5d4c677bc1524374804ced87b4bfb152

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08558005B2