Sodium Hydroxide → Ammonium Hydroxide

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Reaction Steps

To 1-[2-(2-chlorophenyl)ethyl]-4-iodoimidazole-2-carbaldehyde (example 78B) (200 mg, 0.55 mmole) is added trifluoromethanesulfonic acid (2 mL). The purple solution is stirred at room temperature overnight, 4-hydroxy-N-methylpiperidine (190 mg, 1.65 mmole) is added and solution is stirred at room temperature for 2 hours. Water is added and the solution is made alkaline by adding 5N NaOH to pH 10. The aqueous phase is extracted with AcOEt. The organic phase is washed with water, brine, dried over MgSO4, filtered and the solvent removed under reduced pressure. The residue is purified by silica gel chromatography eluting with (CH2Cl2:MeOH) (100:0) to (90:10) then (CH2Cl2:MeOH:NH4OH) (9:1:0.1) to give 8-chloro-2-iodo-4-(1-methyl piperidin-4-yloxy)-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene.

Provenance & Evidence