Reaction #8738

Reaction equation

(3-bromothiophen-2-yl)-(3-methoxyphenyl)methanone oxime

KOH

2-ethoxyethanol

→

title compound

Yield 68.0%

3-(3-methoxyphenyl)thieno[2,3-d]isoxazole

Yield 68.0%

Solvents

hexane

Conditions

Workup

1. 1
   TemperatureReflux
2. 2
   TemperatureHeat the reacton for an additional four hours
3. 3
   ExtractionAdd water and extract the organics into ether
4. 4
   WashWash the ether phase with water
5. 5
   Dryingdry (MgSO4)
6. 6
   Filtrationfilter
7. 7
   Concentrationconcentrate
8. 8
   Otherto yield an oil
9. 9
   OtherPurify the oil by column (alumina) chromatography
10. 10
    Washelute with 15% ether in hexane
11. 11
    Otherto obtain white crystals
12. 12
    OtherRecrystallize the crystals from ether

Procedure

Reflux a mixture of (3-bromothiophen-2-yl)-(3-methoxyphenyl)methanone oxime (10 g, 0.032 mol), KOH (3.6 g, 0.064 mol dissolved in 10 mL water) and 2-ethoxyethanol (40 mL) under nitrogen for one hour at 105–110° C. Add copper chloride (0.16 g, 0.0016 mol) whereupon the reaction mixture becomes dark brown in color. Heat the reacton for an additional four hours. TLC shows that the reaction is complete. Add water and extract the organics into ether. Wash the ether phase with water, dry (MgSO4), filter and concentrate to yield an oil. Purify the oil by column (alumina) chromatography, and elute with 15% ether in hexane to obtain white crystals. Recrystallize the crystals from ether:hexane to yield the title compound (5 g, 68% Yield), m.p. 51–52° C.

Source