tert-Butyl 3-oxo-1-thia-4,8-diazaspiro[4.5]decane-8-carboxylate synthesis

Yield:392331-35-0 51%

Reaction Conditions:

with ammonium carbonate;magnesium sulfate in toluene;

Steps:

90.b 90b)

90b) tert-Butyl 3-oxo-1-thia-4,8-diazaspiro[4.5]decane-8-carboxylate tert-Butyl 4-oxopiperidine-1-carboxylate (4.0 g), thioglycolic acid (2.2 g), ammonium carbonate (1.17 g) and anhydrous magnesium sulfate (1.41 g) were added to toluene (60 ml), and the mixture was refluxed for 2.5 hours. The reaction mixture was diluted with water, and extracted with ethyl acetate. The extract was washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting solid was washed with hexane to obtain the title compound as the colorless crystals (2.79 g, 51%). NMR (CDCl₃) δ: 1.46 (9H, s), 1.87-1.95 (4H, m), 3.06-3.20 (2H,m), 3.58 (2H, s), 3.87-3.97 (2H, m), 6.81 (1H, br s).

References:

US2003/187023,2003,A1