1.1
Reagents:
Trimethyl orthoformate
;
1 h, reflux; cooled
1.2
Solvents:
Dimethylformamide
;
2 h, reflux; reflux → rt
1.3
Solvents:
Water
;
rt
1.4
Solvents:
Diphenyl ether
;
5 min, rt → 300 °C; 300 °C → rt

2881489226