4-Hydroxy-2,2,6,6-tetramethylpiperidine → 2,2,6,6-Tetramethylpiperidin-4-yl 6-(octanoylamino)hexanoate

Participants

Reaction Conditions

Reaction Steps

A 250 mL single-necked reaction flask was equipped with a magnetic stirrer and a Dean-Stark trap fitted with a condenser and nitrogen inlet/outlet. To this flask was charged 6.1 g (22.5 mmol) of compound D, 5.29 g (33.7 mmol) of 2,2,6,6-tetramethyl-4-piperidinol, and 150 mL of toluene. Under a slow nitrogen flow, 8 mL of toluene was distilled off and the trap drained. After lowering the heat source and allowing the mixture to cool to 110° C., 0.17 g (0.28 mmol) of 1,3-diacetoxy-1,1,3,3-tetrabutyldistannoxane was added and the heat source raised. Another 100 mL of toluene was slowly distilled off over 16 hours and the resulting mixture was cooled to room temperature and diluted with methylene chloride. The organic solution was washed with water to remove excess amino alcohol and dried over anhydrous sodium carbonate. Filtration and removal of solvent under reduced pressure followed by further solvent removal in vacuo (<1 mm) at 60° C. gave 8.0 g (90%) of Compound VI as a light brown wax. The structure of the material was confirmed by 1H NMR analysis. 1H NMR (CDCl3): δ 5.60 (m, 1H, NHCO—); 5.18 (m, 1H, R2CHOCO—); 3.25 (dt, 2H, —CH2—NH—); 2.28 (t, 2H, —CH2COO—); 2.16 (t, 2H, —CH2CONH—); 1.95-1.10 (m, 20H, CH2(CH2)3CH2, CH2(CH2)5, CH2CH2C(CH3)2); 1.20 (d, 12H, CH2C(CH3)2; 0.88 (t, 3H, —CH2CH3).

Provenance & Evidence