Reaction #302876

Reaction equation

2-aminobenzimidazole

ethyl methacrylate

→

3,4-dihydro-3-methyl-pyrimidino[1,2-a]benzimidazol-2(1H)-one

Solvents

tert-butyl methyl ether

Conditions

Workup

1. 1
   Temperatureto cool down to room temperature

Procedure

5.326 g (40 mmol) 2-aminobenzimidazole and 4.56 g (40 mmol) ethyl methacrylate were dissolved in 25 ml Proglyde DMM. The reactionmixture is heated to 130° C. The reaction is allowed to continue for 7 hours at 130° C. The reactionmixture is allowed to cool down to room temperature and is added to 250 ml tert-butyl methyl ether. The precipitated 3,4-dihydro-3-methyl-pyrimidino[1,2-a]benzimidazol-2(1H)-one was isolated by filtration and recrystallized from 1-methoxy-2-propanol. 2.7 g (33%) of 3,4-dihydro-3-methyl-pyrimidino[1,2-a]benzimidazol-2(1H)-one was isolated (m.p. >260° C.).

Source