Hydrochloric Acid → HCID 178524153, compound

Participants

Reaction Conditions

Reaction Steps

In a 50 ml round-bottomed flask under argon, dissolve 1 g of [4-(5-methoxycarbonyl-1H-benzimidazol-2-yl)-9H-fluoren-9-one, obtained as in stage 2 of Example 205, in 15 ml of methanol, and then add 5.9 ml of a 1.2M aqueous solution of lithium hydroxide and reflux for 24 hours. Bring to dryness under reduced pressure, add water, cool to 10° C., and then acidify to pH 4-5 with a 1M aqueous solution of hydrochloric acid. The crude product is filtered, washed with water and then dried. The solid obtained is made into a paste with diisopropyl ether, filtered and rinsed. In this way, we obtain 919 mg of 4-(5-carboxy-1H-benzimidazol-2-yl)-9H-fluoren-9-one, in the form of a yellow powder, which is used as it is in the following stage with the following characteristics:

Provenance & Evidence