Boron trifluoride etherate → Ethyl 4-ethylthiazole-5-carboxylate
Reaction equation
N[C:2]1[S:3][C:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])=[C:5]([CH2:7][CH3:8])[N:6]=1.B(F)(F)F.CCOCC.N(OC(C)(C)C)=O.[Na].[OH-].[Na+]>C1COCC1>[CH2:7]([C:5]1[N:6]=[CH:2][S:3][C:4]=1[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH3:8]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
To a 0° C. solution of ethyl 2-amino-4-ethyl-1,3-thiazole-5-carboxylate (2.6 g, 13.0 mmol) in anhydrous THF (40 mL) was added boron trifluoride diethyl etherate (2.0 mL, 16.5 mmol). After 15 minutes of stirring at 0° C., tert-butyl nitrite (7 mL, 59 mmol) was added. The mixture was stirred at 0° C. for 3 hours, and then an aqueous solution of sodium hypophosphonate (4.1 g, 47 mmol, 15 mL) was added. The mixture was stirred at 0° C. for 2 hours and at room temperature overnight. The solution was basified to pH 8-9 with 5 N NaOH and then was extracted with EtOAc (3×75 mL). The organic extracts were combined, dried over MgSO4, filtered, evaporated, and dried in vacuo, affording ethyl 4-ethyl-1,3-thiazole-5-carboxylate (1.91 g, 80% yield). The product was used without further purification.
Workup
- stirringThe mixture was stirred at 0° C. for 3 hours
- stirringThe mixture was stirred at 0° C. for 2 hours and at room temperature overnight
- extractionwas extracted with EtOAc (3×75 mL)
- dry with materialdried over MgSO4
- filtrationfiltered
- customevaporated
- customdried in vacuo
Sources & evidence
- ORD record
- ord-612b154978534a649cd5d029535811f3
- Source dataset
- uspto-grants-2015_05
- Patent number
- US09040538B2
Reaction notes
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