1-Bromo-3-methylbutane → iso-Pentyl 3-iso-pentyloxy-5-nitrobenzoate

HRID 2266939Notes

Reaction equation

HRID 2266939 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([N+:11]([O-:13])=[O:12])[CH:10]=1)[C:5]([OH:7])=[O:6].C([O-])([O-])=O.[K+].[K+].[CH2:20](Br)[CH2:21][CH:22]([CH3:24])[CH3:23]>CN(C=O)C>[CH2:20]([O:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([N+:11]([O-:13])=[O:12])[CH:10]=1)[C:5]([O:7][CH2:2][CH2:3][CH:4]([CH3:8])[CH3:5])=[O:6])[CH2:21][CH:22]([CH3:24])[CH3:23]

Participants

5

Reactant 3

HCID 78911-Bromo-3-methylbutaneHCID 11430Potassium CarbonateHCID 8203933-Hydroxy-5-nitrobenzoic acid

Product 1

HCID 58060846iso-Pentyl 3-iso-pentyloxy-5-nitrobenzoateYield 113.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
90 °C

Procedure

5.15 g (28 mmol) 8 were dissolved in 15 mL DMF (anhydrous, Aldrich) and added to a suspension of 15.5 g (112 mmol, 4 eq.) K2CO3 in 25 mL DMF under nitrogen atmosphere. 13.4 mL (112 mmol, 4 eq.) iso-pentyl bromide were added. The thick, canary-yellow reaction mixture was heated to 90° C. and became stirrable again. It was left at this temperature for at least 8 h. Product formation could be followed by TLC (hexanes/ethyl acetate 9:1, Rf (product)=0.85). After cooling to r.t., DMF was removed with a vacuum rotovap, then ethyl acetate and water were added. After phase separation, the water layer was extracted with ethyl acetate two more times, the organics were pooled, washed with brine, dried with MgSO4, concentrated and put under vacuum overnight. The crude product was purified by column chromatography (hexanes/ethyl acetate 9:1), yielding 5.15 g (80%) of a yellow liquid. 1H NMR (CDCl3) δ 8.42 (dd, J1=1.5 Hz, J2=2.4 Hz, 1H), 7.90 (t, J1=2.4 Hz, J2=2.4 Hz, 1H),7.87 (dd, J1=1.5 Hz, J2=2.4 Hz, 1H), 4.40 (t, J=6.7 Hz, 2H, PhOCH2CH2CH(CH3)2), 4.11 (t, J=6.6 Hz, 2H, PhOCH2CH2CH(CH3)2), 1.93-1.65 (m, 6H), 0.99 (d, J=6.6 Hz, 12H, 2×CH(CH3)2); 13C NMR (CDCl3) 164.38, 159.51, 148.94, 132.69, 121.46, 116.10, 112.87, 67.40, 64.42, 37.38, 37.08, 24.97, 24.77, 22.29; ESI-MS m/z 360 [M+K−2]+, 408 [M+2Na+K], 669 [M2+Na]+.

Workup

  1. waitIt was left at this temperature for at least 8 h
  2. temperatureAfter cooling to r.t.
  3. customDMF was removed with a vacuum rotovap
  4. additionethyl acetate and water were added
  5. customAfter phase separation
  6. extractionthe water layer was extracted with ethyl acetate two more times
  7. washwashed with brine
  8. dry with materialdried with MgSO4
  9. concentrationconcentrated
  10. customput under vacuum overnight
  11. customThe crude product was purified by column chromatography (hexanes/ethyl acetate 9:1)

Sources & evidence

ORD record
ord-ad3d7feadc5b4e49be11ef736b6ae81e
Source dataset
uspto-grants-2010_12
Patent number
US07858737B2

Reaction notes

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