Dimethylformamide → 6-(2-bromo-pyridine-4-carbonyl)-4-methyl-3H-benzoxazol-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

2.20 mL (30.0 mmol) thionyl chloride and 0.390 mL (4.80 mmol) DMF were added to 2.00 g (9.90 mmol) 2-bromopyridine-4-carboxylic acid in 30 mL DCM and refluxed for 2 h. The reaction mixture was evaporated to dryness and coevaporated twice with toluene. The residue was combined with 6.24 g (46.8 mmol) aluminium trichloride and 1.50 g (10.1 mmol) 4-methyl-3H-benzoxazol-2-one and the mixture obtained was stirred overnight at 110° C. and for 5 hours at 130° C. The mixture was decomposed with ice water and extracted twice with DCM. The organic phases were dried on magnesium sulphate, filtered and evaporated down i. vac. The residue was triturated with DIPE/MeOH and suction filtered. The product obtained is a mixture of the corresponding bromine and chlorine compound (40/60).

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