HCID 19347454, compound → HCID 19347460, compound

Participants

Reaction Steps

6,7-Dihydropyrido[1,2-a]benzimidazole-9 (8H)-one prepared in the above (A) was subjected to bromination in the similar manner to that of Example 1, Route 1(C) to give 8-bromo-6,7-dihydropyrido[1,2-a]benzimidazole-9(8H)-one hydrobromide. The resulting compound (17.4 g) and thiourea (6.0 g) were dissolved into absolute ethanol (200 ml), and the solution was heated to reflux for 4 hours. After completion of the reaction, the reaction mixture was cooled and filtered to give solids (10.6 g), which are dihydrobromide of the desired compound. The dihydrobromide was neutralized with 2N-potassium hydroxide in an aqueous system and recrystallized with a mixture of DMF and ethanol to give the titled compound (7.1 g, 56%).

Provenance & Evidence