Réaction #43379

Équation de réaction

5-bromo-thiophene-2-carboxylic acid

thionyl chloride

tert.-butyl 2-amino-isobutyrate hydrochloride

water

→

tert.-butyl 2-[(5-bromo-thiophen-2-yl)-carbonylamino]-isobutyrate

Solvants

dichloromethane

dichloromethane

Conditions de réaction

Traitement

1. 1
   AutreThe mixture is then evaporated down i
2. 2
   Autreevaporated down completely
3. 3
   workup.ADDITIONThe residue is added dropwise to 10 ml dichloromethane
4. 4
   workup.STIRRINGstirred for 16 h
5. 5
   Extractionextracted with dichloromethane
6. 6
   Séchagethe combined organic phases are dried over magnesium sulphate
7. 7
   Autreevaporated down i

Mode opératoire

2.63 g (12.3 mmol) 5-bromo-thiophene-2-carboxylic acid are refluxed in 15 ml dichloromethane together with 7.0 ml of thionyl chloride for 2 h with stirring. The mixture is then evaporated down i. vac. and the residue is twice taken up in toluene and evaporated down completely i. vac. The residue is added dropwise to 10 ml dichloromethane with stirring at ambient temperature in a mixture of 2.41 g (12.3 mmol) tert.-butyl 2-amino-isobutyrate hydrochloride in 20 ml dichloromethane with 5.14 ml (36.9 mmol) TEA and stirred for 16 h. The mixture is poured into water and extracted with dichloromethane, the combined organic phases are dried over magnesium sulphate and evaporated down i. vac.

Source