Réaction #71115

Équation de réaction

N2

1-(2-bromo-thiazol-5-yl)-ethanone

ethylene glycol

trimethylorthoformate

→

title compound

2-Bromo-5-(2-methyl-[1,3]dioxolan-2-yl)-thiazole

Solvants

NaHCO3

Conditions de réaction

Traitement

1. 1
   Extractionthe mixture was extracted with EA (50 mL)
2. 2
   Lavageextracts were washed with brine (2×50 mL)
3. 3
   Séchagedried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   Autrethe solvent was removed under reduced pressure
6. 6
   AutrePurification of the residue by FC (20:1 to 3:1 hept-EA)

Mode opératoire

In a flame dried round-bottomed flask equipped with a magnetic stir bar and a condenser under inert atmosphere (N2), a solution of 1-(2-bromo-thiazol-5-yl)-ethanone (2.20 g, 10.68 mmol) in ethylene glycol (11.46 mL, 205.53 mmol) was treated with trimethylorthoformate (2.39 mL, 21.76 mmol) followed by LiBF4 (204 mg, 2.14 mmol). The reaction mixture was heated at 95° C. for 2 days. Sat. aq. NaHCO3 (50 mL) was added and the mixture was extracted with EA (50 mL). The org. extracts were washed with brine (2×50 mL), dried over MgSO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (20:1 to 3:1 hept-EA) gave the title compound as a yellow oil. TLC:rf (1:1 hept-EA)=0.80. LC-MS-conditions 01: tR=0.84 min; [M+H]+=251.85.

Source