تفاعل #1958248

معادلة التفاعل

3,5-dibromosalicylaldehyde

acetic anhydride

triethylamine

→

6,8-dibromocoumarin

المردود 87.0%

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe reaction solution was heated overnight
2. 2
   درجة الحرارةat reflux under argon
3. 3
   أخرىa solid mass formed
4. 4
   غسيلThe dark brown reaction mixture was washed with hot hexanes (3×300 mL) and aqueous saturated sodium bicarbonate
5. 5
   workup.DISSOLUTIONThe resulting solid was dissolved in EtOAc (2 L)
6. 6
   غسيلwashed with water
7. 7
   تجفيفThe organic layer was dried (sodium sulfate)
8. 8
   تركيزconcentrated
9. 9
   أخرىto give a brown solid
10. 10
    ترشيحthat was collected by filtration
11. 11
    أخرىThe solid was dried in vacuo

الإجراء التجريبي

To a suspension of 3,5-dibromosalicylaldehyde (100 g, 357 mmol) in acetic anhydride (164.8 mL, 1.8 mol) was added triethylamine (45 mL, 375 mmol). The reaction solution was heated overnight at reflux under argon. The solution was cooled to room temperature and a solid mass formed. The dark brown reaction mixture was washed with hot hexanes (3×300 mL) and aqueous saturated sodium bicarbonate. The resulting solid was dissolved in EtOAc (2 L) and washed with water. The organic layer was dried (sodium sulfate) and concentrated to give a brown solid that was collected by filtration. The solid was dried in vacuo to give substantially pure 6,8-dibromocoumarin (94.2 g, 87% yield).

المصدر