Reaction #11283

Reaction equation

2,5-dichloro-N′-[4-(octyloxy)benzoyl]benzohydrazide

p-anisidine

Phosphorus trichloride

1L

methylene chloride DMF

→

3-(2,5-dichlorophenyl)-4-(4-methoxyphenyl)-5-[4-(octyloxy)phenyl]-4H-1,2,4-triazole

Yield 34.0%

3-(2,5-Dichlorophenyl)-4-(4-methoxyphenyl)-5-[4-(octyloxy)phenyl]-4H-1,2,4-triazole

Yield 34.0%

Solvents

1,2-dichlorobenzene

Conditions

Workup

1. 1
   Temperaturereflux condenser and nitrogen inlet
2. 2
   Otherresulted in partial solvation of the solids
3. 3
   workup.DISTILLATIONThe solvent was distilled off under a light vacuum
4. 4
   FiltrationThe solid material was filtered off
5. 5
   workup.DISSOLUTIONdissolved in acetone
6. 6
   workup.ADDITIONEnough heptane was added
7. 7
   Otherto precipitate a purple-colored oily sludge
8. 8
   Otherhad been completely precipitated
9. 9
   OtherThe acetone/heptane layer was decanted off
10. 10
    workup.ADDITIONdiluted further with a large excess of heptane
11. 11
    Otherto precipitate a white solid
12. 12
    FiltrationThis was filtered off
13. 13
    workup.DISSOLUTIONdissolved in acetone
14. 14
    Otherre-precipitated with heptane
15. 15
    FiltrationFiltration
16. 16
    Otherdrying

Procedure

Into a 1L round-bottomed flask fitted with a mechanical stirrer, reflux condenser and nitrogen inlet were introduced 2,5-dichloro-N′-[4-(octyloxy)benzoyl]benzohydrazide (40 g, 0.09146 mole, 1 equivalent), p-anisidine (67.60 g, 0.5487 mole, 6 equivalents) and 300 mL 1,2-dichlorobenzene. Mechanical stirring resulted in partial solvation of the solids. Phosphorus trichloride (12.56 g, 0.0146 mole, 1 equivalent) was added and the contents of the flask heated at 180° C. for 12 hrs. The solvent was distilled off under a light vacuum and the residue transferred to a 2L flask with 1L of a 1:1 acetone/heptane mixture. The solid material was filtered off and dissolved in acetone. Enough heptane was added to precipitate a purple-colored oily sludge. Heptane dilution of a test sample of the acetone/heptane layer ensured that the oily sludge had been completely precipitated. The acetone/heptane layer was decanted off and diluted further with a large excess of heptane to precipitate a white solid. This was filtered off, dissolved in acetone and re-precipitated with heptane. Filtration and drying gave 3-(2,5-dichlorophenyl)-4-(4-methoxyphenyl)-5-[4-(octyloxy)phenyl]-4H-1,2,4-triazole (8) (16.25 g, 34% yield).

Source