Nitric Acid → Ammonia

Into a vessel made of acid-resistant stainless steel of 75 liters capacity, provided with a stirring device and a cooling jacket, a nitrated solution, obtained as in examples I or III, was placed and 6 kg of 2-methylimidazole were gradually introduced, while cooling and stirring, and then 20 liters of nitric acid of 1.40 density were introduced such that the temperature does not exceed 70°. The vessel was closed and connected by a valved conduit to an absorption device, provided with a cooled receiver. Sulphuric acid was gradually introduced until an increase of the temperature to 100° and the start of an intensive reaction was noted, this being associated with the eliminating of great quantities of nitric oxides. The addition of sulphuric acid was interrupted and the temperature maintained at 110°, by intensive cooling and periodic addition of condensates from the receiver, and to initially inhibit the reaction there is added in the first stage 1 liter of nitric acid of a density of 1.40. After stabilization of the reaction speed, a further uniform course of the reaction was maintained by gradual introduction of sulphuric acid to the use of a total amount of 20 liters, by simultaneously periodically filling up the nitrating vessel with the content of the receiver, when the reaction tended to become more violent. After the intensity of the reaction declined, which lasted about 1 hour, the cooling was interrupted and after five minutes the temperature gradually raised to about 140° and a fulfillment of the reaction at this temperature effected until the decline of the exothermic effect, at which time the solution was evaporated and condensed and the volatile components, which were liberated during this period, such as gases and vapors, have not been recycled to the reaction medium. After cooling of the reacted mixture, 1/4 of the volume of the solution was retained for treatment in the same way with the following charge and from the remaining quantity, after neutralization with ammonia, there were obtained 5.820 kg of 2-methyl-5-nitroimidazole corresponding to an output of about 64% of theoretical.

1. temperaturewhile cooling
2. customdoes not exceed 70°
3. customThe vessel was closed
4. customprovided with a cooled receiver
5. temperaturean increase of the temperature to 100°
6. customthe start of an intensive reaction
7. temperaturethe temperature maintained at 110°
8. temperatureby intensive cooling
9. additionperiodic addition of condensates from the receiver
10. customthe reaction there
11. waitthe cooling was interrupted and after five minutes
12. temperaturethe temperature gradually raised to about 140°
13. customa fulfillment of the reaction at this temperature
14. customwas evaporated
15. customcondensed
16. waitthe volatile components, which were liberated during this period, such as gases and vapors
17. temperatureAfter cooling of the reacted mixture, 1/4 of the volume of the solution
18. additionfollowing charge and from the remaining quantity

ORD record

ord-192c21399c9b4b97821becda6ff7b608

Source dataset

uspto-grants-1980_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04209631