2-Chloro-5-nitrobenzoic acid → Tert-butyl 2-chloro-5-nitrobenzoate

HRID 1603034Notes

Reaction equation

HRID 1603034 reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][C:8]([N+:11]([O-:13])=[O:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(Cl)(Cl)=O.[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:8]([N+:11]([O-:13])=[O:12])=[CH:7][C:3]=1[C:4]([O:6][C:19]([CH3:22])([CH3:20])[CH3:18])=[O:5]

Participants

8

Reactant 3

HCID 172872-Chloro-5-nitrobenzoic acidHCID 24386Thionyl ChlorideHCID 23665647Potassium tert-butoxide

Product 1

HCID 10729867Tert-butyl 2-chloro-5-nitrobenzoateYield 78.4%

Reagents, catalysts & solvents 4

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

Conditions

Temperature
0 °C

Procedure

A solution of 2-chloro-5-nitrobenzoic acid (10.14 g, 50.3 mmol), thionyl chloride (4.4 mL, 60 mmol) and DMF (4 drops) in 1,2-dichloroethane (150 mL) was stirred at reflux for 14 h, cooled and evaporated. The 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) added dropwise over 30 min under nitrogen. The mixture was stirred a further 15 min at 0° C., diluted with aq. NaHCO3, extracted with EtOAc (×2), and the extracts dried (Na2SO4) and evaporated. Crystallisation from petroleum ether gave t-butyl 2-chloro-5-nitrobenzoate as a white crystalline solid (10.1 g, 78%), mp 91.5-92° C. 1H NMR (CDCl3) δ8.59 (d, J=2.8 Hz, 1H, H-6), 8.24 (dd, J=8.8, 2.8 Hz, 1H, H-4), 7.63 (d, J=8.8 Hz, 1H, H-3), 1.65 (s, 9H, t-Bu); 13C NMR (CDCl3) d 163.0 (CO2tBu), 146.1, 140.0, 133.3, (C-1,2,5), 132.0, 126.1, 126.0 (C-3,4,6), 84.0 (CMe3), 28.1 (CH3). Anal. Calculated for C11H12ClNO4 : C, 51.3; H, 4.7; N, 5.4; Cl, 13.8. Found: C, 51.3; H, 4.5; N, 5.6; Cl, 14.0%.

Workup

  1. temperatureat reflux for 14 h
  2. temperaturecooled
  3. customevaporated
  4. dissolutionThe acid chloride was dissolved in THF (100 mL)
  5. extractionextracted with EtOAc (×2)
  6. dry with materialthe extracts dried (Na2SO4)
  7. customevaporated
  8. customCrystallisation from petroleum ether

Sources & evidence

ORD record
ord-9c1ba8daa39d40c7aa1ae5e434146753
Source dataset
uspto-grants-1999_11
Patent number
US05985909

Reaction notes

Loading…