Maleic Acid → 1,1'-[4-Methoxy-1,2-phenylenebis(methylene)]bispiperidine dimaleate
Reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][N:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]2)=[C:5]([CH2:16][N:17]2[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]2)[CH:4]=1.[C:23]([OH:30])(=[O:29])/[CH:24]=[CH:25]\[C:26]([OH:28])=[O:27]>C(OCC)C>[C:23]([OH:30])(=[O:29])/[CH:24]=[CH:25]\[C:26]([OH:28])=[O:27].[C:23]([OH:30])(=[O:29])/[CH:24]=[CH:25]\[C:26]([OH:28])=[O:27].[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][N:10]2[CH2:11][CH2:12][CH2:13][CH2:14][CH2:15]2)=[C:5]([CH2:16][N:17]2[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]2)[CH:4]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
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%).
Workup
- customThe crude diamine base (3.0 g.) was then purified by dissolution in chloroform
- extractionfollowed by extraction of the latter solution with ice-cold 3 N aqueous hydrochloric acid
- temperaturecooling) and the resulting organic base
- extractionback extracted into chloroform
- dry with materialAfter drying over anhydrous magnesium sulfate
- filtrationfiltering
- customthere was ultimately obtained a clear chloroform solution that
- concentrationwas subsequently concentrated in vacuo
- customto afford 2.0 g
- filtrationfiltered
- customto afford a pale yellow gum as the product
- customRecrystallization of the latter material twice from isopropyl alcohol/diethyl ether
Sources & evidence
- ORD record
- ord-106ceac8df9144f89f6847b532183025
- Source dataset
- uspto-grants-1983_11
- Patent number
- US04414220
Reaction notes
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