反应详情

A solution of 98.5 parts of 1-[3-{4-[(4-chloro-2-nitrophenyl)amino]-1-piperidinyl}propyl]-1,3-dihydro-3-(1-methylethenyl)-2H-benzimidazol-2-one in 360 parts of methylbenzene is acidified with 2-propanol, previously saturated with gaseous hydrogen chloride. After boiling for a while, an oil precipitates. The supernatant phase is decanted and the residual oil is suspended in water. The suspension is alkalized with a concentrated ammonium hydroxide solution. The product is extracted with methylbenzene. The extract is dried, filtered and evaporated. The residue is crystallized from 4-methyl-2-pentanone. The product is filtered off and dried, yielding 68 parts (75.5%) of 1-[3-{4-[(4-chloro-2-nitrophenyl)amino]-1-piperidinyl}-propyl]-1,3-dihydro-2H-benzimidazol-2-one.

1. customan oil precipitates
2. customThe supernatant phase is decanted
3. extractionThe product is extracted with methylbenzene
4. customThe extract is dried
5. filtrationfiltered
6. customevaporated
7. customThe residue is crystallized from 4-methyl-2-pentanone
8. filtrationThe product is filtered off
9. customdried