Reaktion #55349

Reaktionsgleichung

1,1'-[4-methoxy-1,2-phenylenebis(methylene)]bispiperidine

maleic acid

→

1,1'-[4-methoxy-1,2-phenylenebis(methylene)]bispiperidine dimaleate

Lösungsmittel

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe crude diamine base (3.0 g.) was then purified by dissolution in chloroform
2. 2
   Extraktionfollowed by extraction of the latter solution with ice-cold 3 N aqueous hydrochloric acid
3. 3
   Temperaturcooling) and the resulting organic base
4. 4
   Extraktionback extracted into chloroform
5. 5
   TrocknenAfter drying over anhydrous magnesium sulfate
6. 6
   Filtrationfiltering
7. 7
   Sonstigethere was ultimately obtained a clear chloroform solution that
8. 8
   Einengenwas subsequently concentrated in vacuo
9. 9
   Sonstigeto afford 2.0 g
10. 10
    Filtrationfiltered
11. 11
    Sonstigeto afford a pale yellow gum as the product
12. 12
    SonstigeRecrystallization of the latter material twice from isopropyl alcohol/diethyl ether

Vorschrift

The crude diamine base (3.0 g.) was then purified by dissolution in chloroform, followed by extraction of the latter solution with ice-cold 3 N aqueous hydrochloric acid. The combined acidified aqueous layers were then basified (with the aid of ice-cooling) and the resulting organic base back extracted into chloroform, using four-100 ml. portions of the latter solvent. After drying over anhydrous magnesium sulfate and filtering, there was ultimately obtained a clear chloroform solution that was subsequently concentrated in vacuo to afford 2.0 g. of pure 1,1'-[4-methoxy-1,2-phenylenebis(methylene)]bispiperidine as the free base in the form of a pale-colored residual oil. The pure diamine oil (2.0 g.) was then dissolved in diethyl ether (200 ml.) and filtered, and the filtered solution was subsequently added to a filtered solution of maleic acid (10 g.; 0.086 mole) dissolved in diethyl ether (600 ml.) to afford a pale yellow gum as the product. Recrystallization of the latter material twice from isopropyl alcohol/diethyl ether then gave analytically pure 1,1'-[4-methoxy-1,2-phenylenebis(methylene)]bispiperidine dimaleate, m.p. 124°-126° C. The yield of pure salt amounted to 1.99 g. (9.8%).

Quelle