Methyl 4-aminobenzoate → Methyl 4-pentylaminobenzoate

HRID 1759779Notes

Reaction equation

HRID 1759779 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][CH:3]=1.C([Li])CCC.I[CH2:18][CH2:19][CH2:20][CH2:21][CH3:22].C(=O)(O)[O-].[Na+]>O1CCCC1>[CH2:18]([NH:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:10][CH:11]=1)[CH2:19][CH2:20][CH2:21][CH3:22]

Participants

6

Reactant 4

HCID 12082Methyl 4-aminobenzoateHCID 123351-IodopentaneHCID 516892Sodium BicarbonateHCID 178418339Butyllithium

Product 1

HCID 22600039Methyl 4-pentylaminobenzoateYield 23%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of methyl p-aminobenzoate (0.45 g, 3.0 mmole) in 6 mL tetrahydrofuran (THF) was cooled to −78° C. and treated dropwise with 2.5 M n-butyllithium solution (1.32 mL). The reaction mixture was allowed to warm to 0° C. over a one hour period. Iodopentane (0.78 mL) was introduced at −40° C. and the mixture was stirred at room temperature for 15 hours. The reaction mixture was poured into 50 mL of a saturated aqueous sodium bicarbonate solution and extracted with three portions of 50 mL of ether. The combined organic extracts were dried over MgSO4, filtered and concentrated in vacuo, giving a brown oil. The product was purified by flash chromatography (SiO2, 10%-20% ethyl acetate/hexanes) to provide 140 mg (23%) of methyl 4-pentylaminobenzoate (43) as a pale yellow oil.

Workup

  1. extractionextracted with three portions of 50 mL of ether
  2. dry with materialThe combined organic extracts were dried over MgSO4
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. customgiving a brown oil
  6. customThe product was purified by flash chromatography (SiO2, 10%-20% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-81a832d8813542a0bfcf02c7b336daec
Source dataset
uspto-grants-2005_01
Patent number
US06838472B2

Reaction notes

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