Hydrochloric Acid → 2-Cyclopropyl-6-hydroxypyrimidine-4-carboxylic acid

Temperatur

30 °C

To a mixture of diethyl oxalacetate sodium salt (150 g, 714 mmol) in methanol (300 mL) and water (150 mL) warmed to 30° C. was added 50% aqueous sodium hydroxide (56 g, 700 mmol) in water (60 mL) over 30 minutes, over which time the temperature remained at 25-30° C. and the pH at 11-12. Then the stirred mixture was heated for an additional 30 min at 35° C. To this mixture was added cyclopropanecarboximidamide monohydrochloride (64 g, 530 mol) in portions over 15 minutes. The orange solution was heated to 50° C. over 30 minutes and held at that temperature for 3 h. The reaction mixture was cooled to 35° C., and concentrated hydrochloric acid (ca. 70 g, 0.7 mol) was added gradually (resulting in foaming) over 30 minutes at 30-40° C. until the pH was about 1.5-2.5. The mixture was concentrated with a rotary evaporator at 35-40° C. to remove alcohols, stirred for 3-4 h at 25° C. to complete crystallization of the product. After the mixture was cooled to 0° C. the solid was collected by filtration. The solid washed with water (2×60 mL), suction-dried, and then dried in a vacuum-oven at 60° C. to afford the title compound as a beige solid (ca. 60 g).

1. customremained at 25-30° C.
2. temperatureThen the stirred mixture was heated for an additional 30 min at 35° C
3. temperatureThe orange solution was heated to 50° C. over 30 minutes
4. temperatureThe reaction mixture was cooled to 35° C.
5. custom(resulting in foaming) over 30 minutes at 30-40° C. until the pH was about 1.5-2.5
6. concentrationThe mixture was concentrated with a rotary evaporator at 35-40° C.
7. customto remove alcohols
8. customcrystallization of the product
9. temperatureAfter the mixture was cooled to 0° C. the solid
10. filtrationwas collected by filtration
11. washThe solid washed with water (2×60 mL)
12. customsuction-dried
13. customdried in a vacuum-oven at 60° C.

ORD-Eintrag

ord-b4a48c91ee8a41a2a219c1a5dd170780

Quelldatensatz

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07863220B2