Hydrochloric Acid → Aminocyclopyrachlor-methyl

A 1-L flask equipped with a nitrogen bubbler connected to a trap and caustic-containing scrubber, an addition funnel, reflux condenser and thermocouple, was charged with 6-amino-5-chloro-2-cyclopropyl-4-pyrimidinecarboxylic acid monohydrate (144 g, 0.62 mol) and methanol (500 mL). Thionyl chloride (185 g, 115 mL, 1.58 mol) was added over about 30 minutes with cooling, and then the reaction mixture was heated at 60° C. for 12 h. The resulting mixture was concentrated at 40-45° C./6 kPa to remove excess methanol (about 300 mL), and the reaction mixture was diluted with water (580 mL). Phenolphthalein (5 mg) was added, and 50% aqueous NaOH (80 g, 1.0 mol) was added dropwise with cooling at 10-25° C. to bring the pH to about 9 as indicated by appearance of pink color. Then just enough 1 N aqueous hydrochloric acid was added to extinguish the pink color. The resulting slurry was cooled to 5° C. and filtered. The filtered wet cake was washed with water and dried to constant weight at 50° C./6 kPa to give 123 g (80% yield) of the title compound with 98% purity by HPLC analysis as a solid melting at 147-148° C.

1. customA 1-L flask equipped with a nitrogen bubbler
2. customconnected to a trap
3. additioncaustic-containing scrubber, an addition funnel
4. temperaturereflux condenser
5. temperaturewith cooling
6. concentrationThe resulting mixture was concentrated at 40-45° C./6 kPa
7. customto remove excess methanol (about 300 mL)
8. additionthe reaction mixture was diluted with water (580 mL)
9. additionPhenolphthalein (5 mg) was added
10. temperaturewith cooling at 10-25° C.
11. temperatureThe resulting slurry was cooled to 5° C.
12. filtrationfiltered
13. washThe filtered wet cake was washed with water
14. customdried to constant weight at 50° C./6 kPa

ORD 기록

ord-086ecdb0d73949f48707e62d1609c1e4

출처 데이터셋

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US08198442B2