O.[CH3:2][C:3]1O[C:5]([CH3:14])=[CH:6][C:7](=[O:13])[C:8]=1[C:9]([O:11][CH3:12])=[O:10].[NH2:15][CH:16]1[CH2:21][C:20]([CH3:23])([CH3:22])[NH:19][C:18]([CH3:25])([CH3:24])[CH2:17]1>C1(C)C=CC=CC=1>[CH3:2][C:3]1[N:15]([CH:16]2[CH2:17][C:18]([CH3:25])([CH3:24])[NH:19][C:20]([CH3:23])([CH3:22])[CH2:21]2)[C:5]([CH3:14])=[CH:6][C:7](=[O:13])[C:8]=1[C:9]([O:11][CH3:12])=[O:10]A 500 ml, 3-neck, round-bottom flask is equipped with a mechanical stirrer, thermometer and a Dean-Stark water trap topped with a water cooled condenser. The flask is charged with a mixture of 45.5 g (0.25 moles) of the methyl 2,6-dimethyl-4-oxopyran-3-carboxylate prepared as described above, 39.1 g (0.25 m) 4-amino-2,2,6,6-tetramethylpiperidine, and 300 ml toluene. The stirred mixture in the flask is heated to boiling by means of an oil bath and the water formed during the reaction is collected in the trap. After 4 hours of reflux a total of 3.8 ml water is collected and the flask and its contents are cooled to room temperature. The toluene is removed by means of a rotary evaporator. On standing and cooling the residue deposits crystals of the title product which are further purified by fractional crystallization.
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