反応 #748769

反応方程式

Hydroxy-3-(4-hydroxy-phenyl)-8-methyl-chromen-4-one

Pyridine

acetic anhydride

→

Acetic acid 3-(4-hydroxy-phenyl)-8-methyl-4-oxo-4H-chromen-7-yl ester

反応条件

後処理

1. 1
   workup.STIRRINGupon stirring
2. 2
   workup.ADDITIONThe reaction mixture was poured
3. 3
   温度into chilled
4. 4
   workup.DISTILLATIONdistilled H2O (4 L)
5. 5
   workup.WAITwas left
6. 6
   workup.STIRRINGstirring at room temperature for 30 minutes
7. 7
   ろ過An off-white solid was collected by suction filtration
8. 8
   その他was dried on a freeze dryer for 24 hours
9. 9
   その他When dry

実験手順

Hydroxy-3-(4-hydroxy-phenyl)-8-methyl-chromen-4-one (35.18 g) were combined into a round bottom flask (1 L). Pyridine (38 ml, 2 equivalents) and acetic anhydride (576 ml, 47 equivalents) were added to the round bottom flask while stirring at room temperature. The reaction was monitored by HPLC and was completed instantaneously. There was a change in colour observed, the reaction mixture was dark brown initially and went bright orange with tan brown floccular particles upon stirring. The reaction mixture was poured into chilled, distilled H2O (4 L) and was left stirring at room temperature for 30 minutes. An off-white solid was collected by suction filtration. 1HNMR of the solid in d-CDCl3 indicated it was Acetic acid 3-(4-hydroxy-phenyl)-8-methyl-4-oxo-4H-chromen-7-yl ester with >95% purity The solid was dried on a freeze dryer for 24 hours. When dry, the solid was weighed (31.80 g, 69%).

出典