Reaktion #159219

Reaktionsgleichung

diisopropylethylamine

2-methoxycarbonylamino-3-methyl-butyric acid

HATU

5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester

→

6-(2-methoxycarbonylamino-3-methyl-butyryl)-5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester

Ausbeute 72.2%

Lösungsmittel

ethyl acetate

dimethylformamide

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo the resulting reaction mixture
2. 2
   Waschenwashed with water and brine
3. 3
   Trocknendried (MgSO4)
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe resulting residue was purified by flash chromatography

Vorschrift

To a solution of 2-methoxycarbonylamino-3-methyl-butyric acid (1.11 g, 6.33 mmol) and HATU (2.41 g, 6.34 mmol) in dimethylformamide (13 mL) was added a solution of 5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester (980 mg, 5.3 mmol) in dimethylformamide (13 mL). To the resulting reaction mixture was added diisopropylethylamine (1.85 mL, 10.6 mmol) and the reaction was heated to 60° C. for 16 hours. The reaction was diluted with ethyl acetate, washed with water and brine, dried (MgSO4) and concentrated. The resulting residue was purified by flash chromatography to give 6-(2-methoxycarbonylamino-3-methyl-butyryl)-5-oxa-6-aza-spiro[3.4]octane-7-carboxylic acid ethyl ester (1.31 g, 72%). LCMS-ESI+: calculated for C16H26N2O6: 342.18; observed [M+1]+: 342.90.

Quelle