Trimethyl orthoformate → 6-Bromo-5-chloro-2-methylbenzoxazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-amino-5-bromo-4-chlorophenol (53) (4.746 g, 21.1 mmol), trifluoromethanesulfonic acid Ytterbium (III) salt (130 mg, 1% mol) and trimethyl orthoformate (4.03 ml, 1.5 eq.) in 15 ml EtOH was heated at 90° C. for 1 h. After cooling down to r.t. Crystalline formed was filtered, washed with MeOH, dried to give 4.694 g 54 as pale brown fine needles (yield: 90.3%)

Herkunft & Nachweise