تفاعل #2336552

معادلة التفاعل

3-chloro-2-methoxy-4-nitrotoluene

H2SO4

→

3-chloro-2-methoxy-4-nitrobenzaldehyde

المذيبات

acetic acid

acetic anhydride

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONthe mixture was poured onto ice-water (20 g)
2. 2
   استخلاصthe mixture was extracted with ethyl acetate (2×25 mL)
3. 3
   غسيلThe combined organic phases were washed with brine
4. 4
   تجفيفdried (sodium sulfate)
5. 5
   تركيزconcentrated
6. 6
   درجة الحرارةheated
7. 7
   درجة الحرارةto reflux for 40 minutes
8. 8
   درجة الحرارةUpon cooling
9. 9
   workup.ADDITIONthe mixture was diluted with water (20 mL)
10. 10
    استخلاصextracted with ethyl acetate (2×50 mL)
11. 11
    غسيلThe combined extracts were washed with brine
12. 12
    تجفيفdried (sodium sulfate)
13. 13
    تركيزconcentrated
14. 14
    أخرىThe crude mixture was chromatographed (10% ethyl acetate/hexanes)

الإجراء التجريبي

A solution of 3-chloro-2-methoxy-4-nitrotoluene (1.0 g, 5.0 mmol) in acetic acid (10 mL) and acetic anhydride (10 mL) was cooled to 50° C. and treated with 1 mL conc. H2SO4. Chromium trioxide (1.4 g, 14 mmol) was added in portions over 10 minutes while the reaction temperature was maintained at 0-5° C. After 30 minutes at this temperature, the mixture was poured onto ice-water (20 g) and the mixture was extracted with ethyl acetate (2×25 mL). The combined organic phases were washed with brine, dried (sodium sulfate) and concentrated. The crude bis-acetate was combined with water (10 mL), ethanol (10 mL) and concentrated sulfuric acid (1 mL) and heated to reflux for 40 minutes. Upon cooling, the mixture was diluted with water (20 mL) and extracted with ethyl acetate (2×50 mL). The combined extracts were washed with brine, dried (sodium sulfate) and concentrated. The crude mixture was chromatographed (10% ethyl acetate/hexanes) to give 3-chloro-2-methoxy-4-nitrobenzaldehyde (400 mg, 1.9 mmol): LC/MS (m/z=215).

المصدر