تفاعل #41929

معادلة التفاعل

Methanesulfonylacetone

HCl

6-bromo-2-methyl-4H-3,1-benzoxazin-4-one

→

white crystals

المردود 48.5%

6-Bromo-3-methanesulfonyl-2-methyl-quinolin-4-ol

المردود 48.5%

المذيبات

N,N-dimethylformamide

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةcooled in ice under nitrogen
2. 2
   درجة الحرارةwithout cooling
3. 3
   درجة الحرارةCooled in ice again
4. 4
   workup.STIRRINGstirred
5. 5
   درجة الحرارةwithout cooling for 4 h
6. 6
   درجة الحرارةCooled in ice again
7. 7
   workup.STIRRINGthe resulting red solution was stirred at 20° C. for 15 min
8. 8
   درجة الحرارةAfter cooling
9. 9
   أخرىthe mixture was evaporated thoroughly at 0.1 mbar/50° C
10. 10
    workup.STIRRINGstirred vigorously for 30 min which
11. 11
    ترشيحThis solid was filtered off
12. 12
    غسيلwashed with water (50 mL)

الإجراء التجريبي

Methanesulfonylacetone (12.6 g, 92.9 mmol) was dissolved in N,N-dimethylformamide (200 mL) and cooled in ice under nitrogen. Then potassium tert.butylate (11.7 g, 102 mmol) was added (exothermic 20° C.) and stirring without cooling continued for 15 min. Cooled in ice again, then 6-bromo-2-methyl-4H-3,1-benzoxazin-4-one (example B.1) (22.3 g, 92.9 mmol) was added and then stirred without cooling for 4 h. Cooled in ice again, then potassium tert.butylate (11.7 g, 102 mmol) was added, and the resulting red solution was stirred at 20° C. for 15 min and then heated at 100° C. for 30 min. After cooling, 4 M HCl (30 mL) was added, and the mixture was evaporated thoroughly at 0.1 mbar/50° C. The residue was suspended in water (200 mL) and stirred vigorously for 30 min which led to the formation of a filterable precipitate. This solid was filtered off and washed with water (50 mL). One obtained 14.25 g (48.5%) of white crystals. MS: m/z=315/317 (M+H).

المصدر