2-Hydrazinoethanol → 1H-Pyrazolo(3,4-b)pyridine-1-ethanol, 3-(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)-

HRID 1382889Notes

Reaction equation

Cl[C:2]1[N:24]=[CH:23][CH:22]=[CH:21][C:3]=1[C:4]([C:6]1[CH:11]=[C:10]([C:12]([CH3:15])([CH3:14])[CH3:13])[C:9]([OH:16])=[C:8]([C:17]([CH3:20])([CH3:19])[CH3:18])[CH:7]=1)=O.[NH:25]([CH2:27][CH2:28][OH:29])[NH2:26]>N1C=CC=CC=1>[C:12]([C:10]1[CH:11]=[C:6]([C:4]2[C:3]3[C:2](=[N:24][CH:23]=[CH:22][CH:21]=3)[N:25]([CH2:27][CH2:28][OH:29])[N:26]=2)[CH:7]=[C:8]([C:17]([CH3:20])([CH3:19])[CH3:18])[C:9]=1[OH:16])([CH3:15])([CH3:14])[CH3:13]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of 45.2 g of 4-(2-chloronicotinoyl)2,6-di-tertiary butylphenol and 21 g of 2-hydrazinoethanol in 230 ml of pyridine is refluxed under stirring for 18 hours. After completion of the reaction, the pyridine is concentrated and 140 ml of ethanol and 70 ml of water are added to the residue. The mixture is warmed to dissolve and then cooled to 0° C. The precipitated crystals are collected by filtration, recrystallized from 70% dioxane and then dried to give 40 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1-(2-hydroxyethyl)-1H-pyrazolo[3,4-b]pyridine, melting at 135°-137° C.

Workup

customAfter completion of the reaction
concentrationthe pyridine is concentrated
addition140 ml of ethanol and 70 ml of water are added to the residue
temperatureThe mixture is warmed
dissolutionto dissolve
filtrationThe precipitated crystals are collected by filtration
customrecrystallized from 70% dioxane
customdried

Sources & evidence

ORD record: ord-a8537811a043413d84c6135ae8342a24
Source dataset: uspto-grants-1989_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04808620

Reaction notes

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