Yield:278788-74-2 99%

Reaction Conditions:

with sodium periodate in 1,4-dioxane;methanol;water at 0; for 5.5 h;

Steps:

2 tert-Butyl thiomorpholine-4-carboxylate 1-oxide

Preparation 2
tert-Butyl thiomorpholine-4-carboxylate 1-oxide
In a 250 mL round-bottom flask equipped with a magnetic stirrer were placed powdered sodium metaperiodate (5.68 g, 1.05 eq) and water (50 mL).
The mixture was stirred at RT first and then cooled to 0° C., followed by the addition of tert-butyl thiomorpholine-4-carboxylate (5.08 g, 25 mmol, 1 eq).
Then to this mixture was added dixane (30 mL) and MeOH (40 mL).
The reaction mixture was stirred at 0° C. for 5.5 hours.
It was then filtered through a Buchner funnel, the white solid was washed with CHCl₃ (3λ50 mL), and the resulting water-chloroform filtrate was transferred into a separation funnel.
The lower chloroform was removed and the aqueous layer was extracted with CHCl₃ (3*150 mL).
The organic phases were combined and dried over anhydrous Na₂SO₄ overnight.
The upper clear layer was then decanted and concentrated to give the title compound as white solid (5.41 g, 99%).
¹H NMR (DMSO-d₆) δ: 3.81 (d, J=13.4 Hz, 2H), 3.60 (br. s., 2H), 2.76-2.84 (m, 2H), 2.65-2.71 (m, 2H), 1.41 (s, 9H)

References:

US2015/166518,2015,A1 Location in patent:Paragraph 0070; 0071