Reaction #336833

Reaction equation

hydrochloric acid

diethyl oxalacetate sodium salt

sodium hydroxide

cyclopropanecarboximidamide monohydrochloride

→

title compound

Yield 46.6%

2-cyclopropyl-1,6-dihydro-6-oxo-4-pyrimidinecarboxylic acid

Yield 46.6%

Solvents

methanol

water

water

Conditions

Workup

1. 1
   Otherremained at 25-30° C.
2. 2
   TemperatureThen the stirred mixture was heated for an additional 30 min at 35° C
3. 3
   TemperatureThe orange solution was heated to 50° C. over 30 minutes
4. 4
   TemperatureThe reaction mixture was cooled to 35° C.
5. 5
   Other(resulting in foaming) over 30 minutes at 30-40° C. until the pH was about 1.5-2.5
6. 6
   ConcentrationThe mixture was concentrated with a rotary evaporator at 35-40° C.
7. 7
   Otherto remove alcohols
8. 8
   Othercrystallization of the product
9. 9
   TemperatureAfter the mixture was cooled to 0° C. the solid
10. 10
    Filtrationwas collected by filtration
11. 11
    WashThe solid washed with water (2×60 mL)
12. 12
    Othersuction-dried
13. 13
    Otherdried in a vacuum-oven at 60° C.

Procedure

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).

Source