Reaktion #94269

Reaktionsgleichung

sodium

maleic acid

4-chloro-2-methyl-6-phenyl-2H-pyrazolo[3,4-b]pyridine

3-methyl butanol

→

2-Methyl-4-(3-methylbutoxy)-6-phenyl-2H-pyrazolo[3,4-b]pyridine maleate

Lösungsmittel

ether

ether

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture is refluxed for six hours
2. 2
   Sonstigethe organic layer dried
3. 3
   Sonstigeevaporated in vacuo
4. 4
   Sonstigeto give 20 g
5. 5
   workup.DISSOLUTIONof the oil (0.063 mol.), dissolved in 50 ml
6. 6
   SonstigeThe precipitated maleate of 2-methyl-4-(3-methylbutoxy)-6-phenyl-2H-pyrazolo [3,4-b]pyridine, at first oily, crystallizes
7. 7
   SonstigeRecrystallization from ethyl acetate
8. 8
   Sonstigegives a product which melts at 119°-120°

Vorschrift

To a solution of 1.61 g. of sodium (0.07 mol.) in 200 ml. of 3-methyl butanol, 17.1 g. of 4-chloro-2-methyl-6-phenyl-2H-pyrazolo[3,4-b]pyridine (0.07 mol.) are added and the mixture is refluxed for six hours while stirring. The cooled solution is agitated with water, the organic layer dried and then evaporated in vacuo to give 20 g. (97%) of oil. To 18.5 g. of the oil (0.063 mol.), dissolved in 50 ml. of ether, a solution of 14.6 g. of maleic acid (0.126 mol.) in 500 ml. of ether is added. The precipitated maleate of 2-methyl-4-(3-methylbutoxy)-6-phenyl-2H-pyrazolo [3,4-b]pyridine, at first oily, crystallizes on standing overnight, yield: 24.6 g. (83%); m.p. 114°-116°. Recrystallization from ethyl acetate gives a product which melts at 119°-120°.

Quelle