2-Chloro-4-nitrobenzoic acid → 2-(1,3-Dimethoxy-1,3-dioxopropan-2-yl)-4-nitrobenzoic acid

HRID 580936Notes

Reaction equation

HRID 580936 reaction equation
Cl[C:2]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].C[O-].[Na+].[C:17]([O:24][CH3:25])(=[O:23])[CH2:18][C:19]([O:21][CH3:22])=[O:20]>[Cu]Br>[CH3:22][O:21][C:19](=[O:20])[CH:18]([C:2]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5])[C:17]([O:24][CH3:25])=[O:23]

Participants

5

Reactant 3

HCID 74482-Chloro-4-nitrobenzoic acidHCID 7943Dimethyl malonateHCID 10942334Sodium Methoxide

Product 1

HCID 105900782-(1,3-Dimethoxy-1,3-dioxopropan-2-yl)-4-nitrobenzoic acid

Reagents, catalysts & solvents 1

HCID 24593copper(I) bromideCatalyst

Conditions

Temperature
70 °C

Procedure

A solution of 2-chloro-4-nitrobenzoic acid (75 g, 372 mmol) in dimethyl malonate (900 mL) was sparged with nitrogen for 15 min. Sodium methoxide (48.3 g, 894 mmol) was added in one portion and the contents exothermed to 480° C. Fifteen minutes later, copper (I) bromide (5.4 g, 37 mmol) was added in one portion and the contents heated to 70° C. for 24 hrs. The reaction was 70% complete by nmr, the contents heated to 85° C. for 6 hrs to completely consume the 2-chloro-4-nitrobenzoic. Water (900 mL) was added to the cooled reaction followed by hexanes (900 mL). The aqueous layer was separated, toluene (900 mL) added, filtered through celite, and aqueous layer separated. Fresh toluene (1800 mL) was added to the aqueous layer and the biphasic mixture acidified with 6N aqueous HCl (90 mL). A white precipitate formed and the contents stirred for 18 hrs. The product was filtered off and dried to give a white soid (78.1 g, 70%) mp=153° C.

Workup

  1. customexothermed to 480° C
  2. temperaturethe contents heated to 85° C. for 6 hrs
  3. customto completely consume the 2-chloro-4-nitrobenzoic
  4. additionWater (900 mL) was added to the cooled reaction
  5. customThe aqueous layer was separated
  6. additiontoluene (900 mL) added
  7. filtrationfiltered through celite, and aqueous layer
  8. customseparated
  9. additionFresh toluene (1800 mL) was added to the aqueous layer
  10. customA white precipitate formed
  11. filtrationThe product was filtered off
  12. customdried
  13. customto give a white soid (78.1 g, 70%) mp=153° C.

Sources & evidence

ORD record
ord-53ca45c7bf1f45ef8786d2aa0bee8b5b
Source dataset
uspto-grants-1999_07
Patent number
US05919795

Reaction notes

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