Ammonia → 5-(Benzoxazol-2-yl)-2-methyl-1-phenylbenzimidazole
Reaction equation
[CH3:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[C:5]2[CH:13]=[CH:14][C:15]([C:17](O)=[O:18])=[CH:16][C:4]=2[N:3]=1.[NH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][C:22]=1O.N>>[O:18]1[C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=2[N:20]=[C:17]1[C:15]1[CH:14]=[CH:13][C:5]2[N:6]([C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=3)[C:2]([CH3:1])=[N:3][C:4]=2[CH:16]=1Participants
4
Conditions
- Temperature
- 160 °C
Procedure
A 2-neck flask (20 mL) equipped with reflux condenser was charged with 2-methyl-1-phenylbenzimidazole-5-carboxylic acid (see Synthesis Example 1-3) (0.15 g, 0.59 mmol), 2-aminophenol (0.09 g, 0.82 mmol) and polyphosphoric acid (approx. 2 g), and this was heated to 160° C. and stirred under those conditions for 20 hours. After being allowed to cool to room temperature, ice was added and concentrated aqueous ammonia (28%) was added to the liquid to give approx. pH 9. The precipitated crystals were filtered off, these were washed with distilled water (approx. 3 mL, 2 times), and then dried to yield the title compound (0.13 g, 68% yield) as greenish pale yellow crystals.