Ammonia → HCID 12115518, compound

Temperature

10 °C

To a flask having an inner volume of 25 ml and equipped with a stirring device, a thermometer and a reflux condenser were charged, 2.97 g (20 mmol) of 3,3-dimethoxy-2-hydroxyiminopropionitrile with a purity of 96.9% by weight synthesized in the same manner as in Example 1, 2.70 g (21 mmol) of t-butylhydrazine hydrochloride with a purity of 97% by weight, 1.4 ml of water, 6 ml of methanol and 1.3 ml (15 mmol) of conc. hydrochloric acid, and the mixture was reacted at 60 to 62° C. for 3 hours. After completion of the reaction, 5 ml of water was added to the mixture and the mixture was cooled up to 10° C. Then, 2.3 ml (37.9 mmol) of 28% by weight aqueous ammonia was gradually added dropwise to the mixture, and the resulting mixture was stirred for 30 minutes while maintaining the liquid temperature to 5° C. or lower. Precipitated crystals were collected by filtration, and then, the crystals were washed with 1.2 ml of cold water and 1.2 ml of cold methanol, and dried under reduced pressure to obtain 1.93 g of 5-amino-1-t-butyl-4-nitrosopyrazole (Isolation yield: 55.2%) as reddish orange solid with a purity of 96.2% by weight (absolute calibration curve method by high performance liquid chromatography).

1. customTo a flask having
2. customan inner volume of 25 ml and equipped with a stirring device
3. additiona thermometer and a reflux condenser were charged
4. customthe mixture was reacted at 60 to 62° C. for 3 hours
5. additionwas added to the mixture
6. temperaturewhile maintaining the liquid temperature to 5° C.
7. customPrecipitated crystals
8. filtrationwere collected by filtration
9. washthe crystals were washed with 1.2 ml of cold water and 1.2 ml of cold methanol
10. customdried under reduced pressure

ORD record

ord-025cd97c8b234b3f8e9ec491d591a917

Source dataset

uspto-grants-2007_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07227032B2