Reaktion #997418

Reaktionsgleichung

Sodium sulfate

2-bromo-4,N-dimethyl-N-methoxybenzamide

Diisobutylaluminum hydride

Methanol

ammonium chloride

→

title compound

5-(2-Bromo-4-methylphenyl)-1,3-oxazole

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred at room temperature for 1 hour
2. 2
   workup.STIRRINGby further stirring for 1 hour
3. 3
   SonstigeThe precipitated matter was removed through filtration by use of Celite
4. 4
   Sonstigethe filtrate was purified

Vorschrift

1-Hydroxybenzotriazole (3.78 g), 4-dimethylaminopyridine (3.42 g), and N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide hydrochloride (5.40 g) were added to a solution (100 mL) of 2-bromo-4-methylbenzoic acid (5.00 g) and N,O-dimethylhydroxylamine hydrochloride (2.73 g) in dichloromethane, followed by stirring at room temperature for 13 hours. 1N Hydrochloric acid was added to the reaction mixture, followed by extraction with dichloromethane and evaporation of the solvent. After purification, 2-bromo-4,N-dimethyl-N-methoxybenzamide (6.0 g) was yielded. The 2-bromo-4,N-dimethyl-N-methoxybenzamide (6.0 g) was dissolved in an anhydrous tetrahydrofuran solution (50 mL) under a stream of argon. Diisobutylaluminum hydride (24.7 mL, 0.93M hexane solution) was added dropwise to the solution at −78° C., and the mixture was stirred at the same temperature for 2 hours. Methanol (5 mL) was added dropwise to the reaction mixture, and an aqueous saturated ammonium chloride solution (5 mL) was added thereto, the mixture was stirred at room temperature for 1 hour. Sodium sulfate anhydrate was added to the reaction mixture, followed by further stirring for 1 hour. The precipitated matter was removed through filtration by use of Celite, and the filtrate was purified, to thereby yield 2-bromo-4-methylbenzaldehyde (4.0 g). The procedure of Referential Example 9 was repeated, except that 2-bromo-4-methylbenzaldehyde (4.0 g) was used, to thereby yield the title compound (3.7 g).

Quelle