4-Chloro-3-nitrobenzoic acid → Tert-butyl 4-chloro-3-nitrobenzoate

HRID 1603031Notes

Reaction equation

HRID 1603031 reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].O=S(Cl)Cl.[CH3:18][C:19]([CH3:22])([O-])[CH3:20].[K+]>CN(C=O)C.ClCCCl.C1COCC1.C([O-])(O)=O.[Na+]>[Cl:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([O:8][C:19]([CH3:22])([CH3:20])[CH3:18])=[O:7])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12]

Participants

8

Reactant 3

HCID 73204-Chloro-3-nitrobenzoic acidHCID 24386Thionyl ChlorideHCID 23665647Potassium tert-butoxide

Product 1

HCID 10611184Tert-butyl 4-chloro-3-nitrobenzoateYield 89%

Reagents, catalysts & solvents 4

HCID 6228DimethylformamideCatalystHCID 111,2-DichloroethaneSolventHCID 8028TetrahydrofuranSolventHCID 516892Sodium BicarbonateSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 4-chloro-3-nitrobenzoic acid (10.03 g, 50 mmol), SOCl2 (4.4 mL, 60 mmol) and DMF (4 drops) in 1,2-dichloroethane (150 mL) was stirred under reflux for 14 h, cooled and evaporated. The resulting crude acid chloride was dissolved in THF (100 mL), cooled to 0° C., and a solution of potassium t-butoxide (5.57 g, 50 mmol) in THF (150 mL) was added dropwise over 30 min under nitrogen. The mixture was stirred a further 15 min at 0° C., diluted with aqueous NaHCO3 and extracted with EtOAc (×2), and the extracts were dried (Na2SO4) and evaporated. Flash chromatography of the residue on silica gel (petroleum ether/EtOAc; 30:1) gave t-butyl 4-chloro-3-nitrobenzoate as a white crystalline solid (11.45 g, 89%), mp (petroleum ether) 70-71° C. 1H NMR (CDCl3) δ8.42 (d, J=2.0 Hz, 1H, H-2), 8.11 (dd, J=8.4, 2.0 Hz, 1H, H-6), 7.61 (d, J=8.4 Hz, 1H, H-5), 1.61 (s, 9H, t-Bu). Anal. Calculated for C11H12ClNO4 : 51.3; H, 4.7; N, 5.4; Cl, 13.8. Found: C, 51.6; H, 4.8; N, 5.4; Cl, 14.0%.

Workup

  1. temperatureunder reflux for 14 h
  2. temperaturecooled
  3. customevaporated
  4. dissolutionThe resulting crude acid chloride was dissolved in THF (100 mL)
  5. extractionextracted with EtOAc (×2)
  6. dry with materialthe extracts were dried (Na2SO4)
  7. customevaporated

Sources & evidence

ORD record
ord-48eacc021320457baab1b81d2cde7465
Source dataset
uspto-grants-1999_11
Patent number
US05985909

Reaction notes

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