ethyl 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)propanoate → 3-(1,3,5-Trimethyl-1H-pyrazol-4-yl)-propionaldehyde

HRID 220463Notes

Reaction equation

HRID 220463 reaction equation
C([O:3][C:4](=O)[CH2:5][CH2:6][C:7]1[C:8]([CH3:14])=[N:9][N:10]([CH3:13])[C:11]=1[CH3:12])C.[H-].C([Al+]CC(C)C)C(C)C>O1CCCC1.C1(C)C=CC=CC=1>[CH3:13][N:10]1[C:11]([CH3:12])=[C:7]([CH2:6][CH2:5][CH:4]=[O:3])[C:8]([CH3:14])=[N:9]1

Participants

5

Reactant 2

HCID 16394809ethyl 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)propanoateHCID 21225700Diisobutylaluminumhydride4×

Product 1

HCID 866416503-(1,3,5-Trimethyl-1H-pyrazol-4-yl)-propionaldehyde

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent4×HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

Dissolve 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)-propionic acid ethyl ester (1.94 g, 9.23 mmol) in tetrahydrofuran (78 mL). Cool to −78° C. in a dry ice/acetone bath and treat dropwise with 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for one hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for one hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for 1 hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for 1 hr. and quench with aqueous saturated potassium sodium tartrate tetrahydrate solution. Add ethyl acetate (150 mL), and stir for 3 hr. at room temperature. Separate organic layer, extract aqueous layer 3 times with ethyl acetate, dry (magnesium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 1:1 to 100% ethyl acetate:hexanes), to give the title preparation (760 mg, 51%). GC-MS m/z=166 [M+].

Workup

  1. customreaction mixture at −78° C. for one hr
  2. stirringStir
  3. customreaction mixture at −78° C. for one hr
  4. stirringStir
  5. customreaction mixture at −78° C. for 1 hr
  6. stirringStir
  7. customreaction mixture at −78° C. for 1 hr
  8. customand quench with aqueous saturated potassium sodium tartrate tetrahydrate solution
  9. stirringAdd ethyl acetate (150 mL), and stir for 3 hr
  10. customat room temperature
  11. extractionSeparate organic layer, extract aqueous layer 3 times with ethyl acetate
  12. dry with materialdry (magnesium sulfate)
  13. filtrationfilter
  14. concentrationconcentrate
  15. custompurify
  16. wash(silica gel chromatography, eluting with 1:1 to 100% ethyl acetate:hexanes)
  17. customto give the title
  18. custompreparation (760 mg, 51%)

Sources & evidence

ORD record
ord-8358c0e1500842d59b67613cb175d4ec
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

Loading…