2,7-diazaspiro[4.5]decane synthesis

Yield:40865-50-7 48%

Reaction Conditions:

with lithium aluminium tetrahydride in tetrahydrofuran at 0; for 48 h;Inert atmosphere;Reflux;

Steps:

32

4.32
2,7-Diazaspiro[4.5]decane (7)
Bisimide 33 (1.7 g; 8.67 mmol) was suspended in dry THF (30 mL) in 0-5 °C under N₂ and 1 M solution of LiAlH₄ in THF (40 mL; 40 mmol) was added dropwise.
The ice bath was removed and the mixture was heated in reflux for 2 days under N₂.
It was cooled to 0-5 °C, diluted with THF (10 mL) and the following were slowly added dropwise in 0-5 °C: water (1.8 mL), 15% NaOH aq (1.8 mL) and water (5.5 mL).
The resulting slurry was filtered through Celite, the solids were washed with THF (250 mL) and the combined filtrates were concentrated in vacuo to give a yellow oil, which was distilled under vacuum (bp 70 °C at 1.0 mmHg) to give the product 7 (580 mg; 48%) as a colourless oil. δ_H (400 MHz, CD₃OD) 2.88, 2.86 (2H, 2d, J 7.1, CH₂NH five-membered), 2.74 (1H, d, J 11.4, CH₂NH), 2.74-2.65 (2H, m, CH₂CH₂NH), 2.65-2.58 (2H, m, CH₂CH₂CH₂NH), 2.57 (1H, d, J 11.4, CH₂NH six-membered), 1.72-1.45 (6H, m, CH₂CH₂CH₂NH, CH₂CH₂CH₂NH, CH₂CH₂NH); δ_C (100.5 MHz, CD₃OD) 56.1 (), 54.6 (CH₂NH), 45.6 (CH₂CH₂CH₂NH), 45.2 (CH₂CH₂NH), 42.5 (C 4°), 36.8 (CH₂CH₂NH), 35.1 (CH₂CH₂CH₂NH), 23.8 (CH₂CH₂CH₂NH); m/z (CI) 141 (M+H⁺); HRMS: found: M+H⁺, 141.1385. C₈H₁₇N₂ requires 141.1392.

References:

Weinberg, Kamil;Stoit, Axel;Kruse, Chris G.;Haddow, Mairi F.;Gallagher, Timothy [Tetrahedron,2013,vol. 69,# 23,p. 4694 - 4707]