Reaction #82521

Reaction equation

sodium hydride

ethyl 2-methylcarbonyl-5-(2,5-dichlorophenyl)-4-hexenoate

guanidine hydrochloride

→

2-amino-4-hydroxy-6-methyl-5-[3-(2,5-dichlorophenyl)-2-butenyl]pyrimidine

Yield 96.6%

Solvents

ethanol

ethanol

Conditions

Workup

1. 1
   workup.ADDITIONTo this is then added dropwise
2. 2
   workup.ADDITIONUpon completion of addition
3. 3
   Temperaturethe reaction mixture is warmed
4. 4
   Temperatureto reflux where it
5. 5
   TemperatureAfter this time the reaction mixture is cooled
6. 6
   Concentrationconcentrated under reduced pressure to a residual oil
7. 7
   workup.STIRRINGThe oil is stirred with 40 mL of aqueous 10% acetic acid
8. 8
   Washthe acid wash
9. 9
   Otheris decanted from the oil
10. 10
    workup.DISSOLUTIONThe oil is dissolved in hot ethanol
11. 11
    FiltrationThe resultant solid is collected by filtration

Procedure

Under a nitrogen atmosphere, a solution of 5.0 grams (0.015 mole) of ethyl 2-methylcarbonyl-5-(2,5-dichlorophenyl)-4-hexenoate in 70 mL of ethanol is stirred, and 3.1 grams (0.032 mole) of guanidine hydrochloride is added. To this is then added dropwise a mixture of 1.5 grams (0.038 mole) of sodium hydride (60% in mineral oil) in 30 mL of ethanol. Upon completion of addition, the reaction mixture is warmed to reflux where it is stirred for about 18 hours. After this time the reaction mixture is cooled and concentrated under reduced pressure to a residual oil. The oil is stirred with 40 mL of aqueous 10% acetic acid, and the acid wash is decanted from the oil. This is repeated with an additional 40 mL of aqueous 10% acetic acid, and then with two 30 mL portions of water. The oil is dissolved in hot ethanol and the solution is placed in a refrigerator. The resultant solid is collected by filtration, yielding 4.7 grams of 2-amino-4-hydroxy-6-methyl-5-[3-(2,5-dichlorophenyl)-2-butenyl]pyrimidine, mp>250° C. The NMR spectrum is consistent with the proposed structure.

Source