[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([CH:7]=O)[CH:2]=1.[CH3:9][N:10]1[C:18]2[CH2:17][CH2:16][CH2:15][C:14](=[O:19])[C:13]=2[CH:12]=[CH:11]1.CC(C)([O-])C.[K+].Cl>CC(O)(C)C>[CH3:9][N:10]1[C:18]2[CH:17]=[CH:16][C:15]([CH2:7][C:3]3[CH:2]=[N:1][CH:6]=[CH:5][CH:4]=3)=[C:14]([OH:19])[C:13]=2[CH:12]=[CH:11]1
500 cm3 of 2-methyl-2-propanol, 75 g of pyridine-3-carboxaldehyde and 100 g of 1-methyl-1,5,6,7-tetrahydroindol-4-one were introduced into a 1-liter reactor equipped with a mechanical stirrer and surmounted by a condenser and a thermometer. After 10 minutes of stirring, 157 g of potassium tert-butoxide were added in small portions over 15 minutes. Following addition, the temperature was held at 75° C. for 1 hour. The reaction mixture was allowed to return to room temperature and then was neutralized (pH=6) with 20% hydrochloric acid. It was poured into 2 kg of ice-water. The precipitate obtained was filtered off with suction and washed with diisopropyl ether and with petroleum ether. It was dried over potash under vacuum at 30° C. This gave 120 g of 1-methyl-5-pyridin-3-ylmethyl-1H-indol-4-ol with a yield of 74%.
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