Org. Synth. 1955, 35, 58
DOI: 10.15227/orgsyn.035.0058
2-(DIMETHYLAMINO)PYRIMIDINE
[Pyrimidine,2-dimethylamino-]
Submitted by C. G. Overberger, Irving C. Kogon, and Ronald Minin
1.
Checked by Charles C. Price and T. L. V. Ulbricht.
1. Procedure
In a
250-ml. three-necked flask equipped with a
reflux condenser and a
gas-inlet tube are placed
45.6 g. (0.4 mole) of 2-chloropyrimidine (p. 182) and
150 ml. of absolute ethanol. The mixture is refluxed for 6 hours while anhydrous
dimethylamine is bubbled into the solution
(Note 1). The solution is cooled, and
100 ml. of ethanol is removed by distillation using a
water aspirator. The residue is chilled in an
ice bath for 1 hour, and
75 ml. of ether is added to cause precipitation of
dimethylamine hydrochloride. After the removal of
dimethylamine hydrochloride and solvent, the residue is distilled at reduced pressure from a
Claisen flask (Note 2). The fraction boiling at
85–86°/28 mm. is collected; yield
40–42.5 g. (
81–86%),
n25D 1.5420
(Note 3).
2. Notes
1.
Anhydrous
dimethylamine may be conveniently prepared by allowing
25% aqueous dimethylamine to drop onto solid
potassium hydroxide, the gas evolved being dried by passage over solid
potassium hydroxide.
2.
The compound is hygroscopic, and care should be taken to prevent exposure to air.
3.
N-Methylaminopyrimidine is similarly prepared; b.p.
96–98°/28 mm., m.p.
57.5–58.5° (
65% yield).
3. Discussion
Similar procedures for this preparation have been reported by Brown and Short
2 and by Copenhaver and Kleinschmidt.
3
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
ethanol (64-17-5)
ether (60-29-7)
potassium hydroxide (1310-58-3)
dimethylamine (124-40-3)
dimethylamine hydrochloride (506-59-2)
2-Chloropyrimidine (1722-12-9)
2-(Dimethylamino)pyrimidine,
Pyrimidine,2-dimethylamino- (5621-02-3)
N-Methylaminopyrimidine
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