Reaktion #9188

Reaktionsgleichung

benzyl chloroformate

ethyl-2-amino-4-methyl-thiazole-5-carboxylate

NaHCO3

Benzyl chloroformate

→

title compound

Ausbeute 48.0%

Ethyl-2-benzyloxycarbonyloxyamino-4-methyl-thiazole-5-carboxylate

Ausbeute 48.0%

Lösungsmittel

THF

dichloromethane

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe organic layer was separated
2. 2
   Trocknendried (MgSO4)
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe residue was chromatographed on a silica gel column
6. 6
   WaschenElution with 10% EtOAc in hexanes

Vorschrift

A 3 M aq. NaHCO3 solution (10 mL, 30 mmol) was added to a stirred solution of ethyl-2-amino-4-methyl-thiazole-5-carboxylate (372 mg, 2 mmol) in THF (20 mL) at 0–5° C. Benzyl chloroformate (500 μL) was added. After 2 h, additional benzyl chloroformate (500 μL) and the biphasic solution was stirred for an additional 2 h at 0–5° C. The mixture was diluted with dichloromethane (50 mL) and water (30 mL). The organic layer was separated, dried (MgSO4), filtered and concentrated. The residue was chromatographed on a silica gel column. Elution with 10% EtOAc in hexanes followed by 20% and 30% EtOAc in hexanes afforded the title compound (310 mg, 48%) as a white solid.

Quelle