Boron trifluoride → 5-(5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-3-(4-tolyl)-1,2,4-oxadiazole

HRID 346290Notes

Reaction equation

HRID 346290 reaction equation
[CH3:1][C:2]1([CH3:17])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[C:6]([C:14](Cl)=[O:15])[CH:5]=[CH:4][C:3]1=2.[CH3:18][C:19]1[CH:28]=[CH:27][C:22]([C:23](=[N:25]O)[NH2:24])=[CH:21][CH:20]=1.B(F)(F)F>O1CCOCC1>[CH3:1][C:2]1([CH3:17])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[C:6]([C:14]3[O:15][N:25]=[C:23]([C:22]4[CH:27]=[CH:28][C:19]([CH3:18])=[CH:20][CH:21]=4)[N:24]=3)[CH:5]=[CH:4][C:3]1=2

Participants

5

Reactant 3

HCID 6356Boron trifluorideHCID 209113N'-Hydroxy-4-methylbenzenecarboximidamideHCID 27954665,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl chloride

Product 1

HCID 147265445-(5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-3-(4-tolyl)-1,2,4-oxadiazoleYield 30.8%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

8.0 g (30 millimoles) of 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthoyl chloride and 4.5 g (30 millimoles) of 4-methylbenzamidoxime in 250 ml of dioxane were refluxed for 1 hour. 1 ml of boron trifluoride dietherate were added and refluxing was continued for a further 4 hours. The mixture was allowed to cool, poured onto ice/water and extracted with methylene chloride. The organic phase was washed several times with water, dried over magnesium sulfate and evaporated down. The oily residue was purified by column chromatography (silica gel; n-heptane +0.5% of ethyl acetate), and the crude product obtained from the first fractions was recrystallized from methanol to give 3.2 g of the title compound of melting point 106°-109° C.

Workup

  1. temperaturerefluxing
  2. temperatureto cool
  3. additionpoured onto ice/water
  4. extractionextracted with methylene chloride
  5. washThe organic phase was washed several times with water
  6. dry with materialdried over magnesium sulfate
  7. customevaporated down
  8. customThe oily residue was purified by column chromatography (silica gel; n-heptane +0.5% of ethyl acetate)
  9. customthe crude product obtained from the first fractions
  10. customwas recrystallized from methanol

Sources & evidence

ORD record
ord-6e7318013dd442b58c22effb8ebd67c3
Source dataset
uspto-grants-1991_10
Patent number
US05061705

Reaction notes

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