Reaction #336834

Reaction equation

hydrochloric acid

diethyl oxalacetate sodium salt

sodium hydroxide

cyclopropanecarboximidamide monohydrochloride

→

title compound

Yield 58.4%

2-cyclopropyl-1,6-dihydro-6-oxo-4-pyrimidine-carboxylic acid

Yield 58.4%

Solvents

methanol

water

water

Conditions

Workup

1. 1
   Otherremained at 25-30° C.
2. 2
   TemperatureThe orange solution was heated to 50° C. over 30 minutes
3. 3
   TemperatureThe reaction mixture was cooled to 30° C.
4. 4
   Concentrationconcentrated to half volume at reduced pressure at 35-40° C.
5. 5
   Other(resulting in foaming) over 30 minutes at 25-30° C. until the pH was about 1-2
6. 6
   Othercrystallization of the product
7. 7
   TemperatureAfter the mixture was cooled to 0° C. the solid
8. 8
   Filtrationwas collected by filtration
9. 9
   WashThe solid washed with water (3×60 mL)
10. 10
    Othersuction-dried
11. 11
    Otherdried in a vacuum-oven at 70° C.

Procedure

To a mixture of diethyl oxalacetate sodium salt (210 g, 950 mmol) in methanol (500 mL) and water (400 mL) was added 50% aqueous sodium hydroxide (80 g, 1.0 mol) 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 30° C. To this mixture was added cyclopropanecarboximidamide monohydrochloride (110 g, 910 mol). The orange solution was heated to 50° C. over 30 minutes and held at that temperature for 5 h. The reaction mixture was cooled to 30° C. and concentrated to half volume at reduced pressure at 35-40° C. and concentrated hydrochloric acid (140 g, 1.4 mol) was added gradually (resulting in foaming) over 30 minutes at 25-30° C. until the pH was about 1-2. The mixture was stirred at 5° C. for 1 h 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 (3×60 mL), suction-dried, and then dried in a vacuum-oven at 70° C. to afford the title compound as a beige solid (100 g); m.p. 235-236° C. (dec.).

Source