Reacción #5331

Ecuación de reacción

Methyl 3,4-diamino-5-methylthiophene-2-carboxylate

triphosgene

→

title compound

Methyl 1,3-dihydro-4-methyl-2-oxo-thieno[3,4-d]imidazole-6-carboxylate

Disolventes

N,N-dimethyl formamide

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroprecipitates
2. 2
   Filtraciónwere collected by filtration
3. 3
   Lavadowashed with dichloromethane
4. 4
   Otrodried
5. 5
   workup.ADDITIONTo the suspension was added sodium hydride (60% in oil; 0.55 g)
6. 6
   workup.STIRRINGthe mixture was stirred for three days at room temperature
7. 7
   OtroThe solvent was evaporated under reduced pressure
8. 8
   workup.ADDITIONTo the residue was added 2N-HCl
9. 9
   OtroResulting
10. 10
    Otroprecipitates
11. 11
    Filtraciónwere collected by filtration
12. 12
    Lavadowashed with water, ether and methanol successively
13. 13
    Otroby drying

Procedimiento

Methyl 3,4-diamino-5-methylthiophene-2-carboxylate (3.0 g) was dissolved in a mixture of N,N-dimethyl formamide (5 ml) and dichloromethane (15 ml). To the solution was added triphosgene (2.4 g) in portions. The mixture was stirred for two days at room temperature, and precipitates were collected by filtration, washed with dichloromethane and dried. Resultant white powder (2.4 g) was suspended in N,N-dimethylformamide (25 ml). To the suspension was added sodium hydride (60% in oil; 0.55 g), and the mixture was stirred for three days at room temperature. The solvent was evaporated under reduced pressure. To the residue was added 2N-HCl. Resulting precipitates were collected by filtration, washed with water, ether and methanol successively, followed by drying to afford the title compound (82 g, 53%) as pale brown powder.

Fuente