Sodium Hydroxide → HCID 67220457, compound
Reaction equation
O[C:2]1[C:7]2[N:8]([CH2:12][CH2:13][O:14][CH3:15])[C:9]([CH3:11])=[N:10][C:6]=2[CH:5]=[C:4]([C:16]([O:18][CH3:19])=[O:17])[C:3]=1[CH2:20][CH2:21][CH:22]([OH:29])[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1.[OH-].[Na+]>P(=O)(O)(O)O>[CH3:15][O:14][CH2:13][CH2:12][N:8]1[C:7]2[C:2]3[O:29][CH:22]([C:23]4[CH:24]=[CH:25][CH:26]=[CH:27][CH:28]=4)[CH2:21][CH2:20][C:3]=3[C:4]([C:16]([O:18][CH3:19])=[O:17])=[CH:5][C:6]=2[N:10]=[C:9]1[CH3:11]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 80 °C
Procedure
A suspension of methyl 7-hydroxy-6-(3-hydroxy-3-phenylpropyl)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (2.00 g, 5.01 mmol, Step 10) in 85% phosphoric acid (40 mL) was stirred at 80° C. for 20 minutes. After cooling to room temperature, the mixture was poured onto ice-water (300 mL), and the solution was neutralized by 10 N sodium hydroxide aqueous solution. The aqueous layer was extracted with dichloromethane. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with ethyl acetate/methanol (gradient elution from ethyl acetate only to 20:1) to afford the title compound as a pale brown solid (1.47 g, 77%).