1.1
Reagents:
Phosphoric tribromide
Solvents:
Dichloromethane
;
rt
1.2
Reagents:
Pyridine
Solvents:
Dichloromethane
;
rt; 4 h, 25 °C
1.3
Reagents:
Sodium hydroxide
Solvents:
Water
;
25 °C → 80 °C; 10 h, 80 °C

2881489226 

