Hydrochloric Acid → Methyl 2-ethoxy-4-nitrobenzoate

HRID 467807Notes

Reaction equation

HRID 467807 reaction equation
O[C:2]1C=C([N+]([O-])=O)C=C[C:3]=1C(O)=O.S(Cl)(Cl)=O.[OH:18][C:19]1[CH:28]=[C:27]([N+:29]([O-:31])=[O:30])[CH:26]=[CH:25][C:20]=1[C:21]([O:23][CH3:24])=[O:22].C(=O)([O-])[O-].[K+].[K+].BrCC.Cl>CO.CN(C=O)C.O>[CH2:2]([O:18][C:19]1[CH:28]=[C:27]([N+:29]([O-:31])=[O:30])[CH:26]=[CH:25][C:20]=1[C:21]([O:23][CH3:24])=[O:22])[CH3:3]

Participants

10

Reactant 6

HCID 313Hydrochloric AcidHCID 6332Ethyl BromideHCID 11430Potassium CarbonateHCID 24386Thionyl ChlorideHCID 692664-Nitrosalicylic acidHCID 139539Salicylic acid, 4-nitro-, methyl ester

Product 1

HCID 9964566Methyl 2-ethoxy-4-nitrobenzoateYield 26.2%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
50 °C

Procedure

4.05 g (21.7 mmol, 1 eq) 2-hydroxy-4-nitro-benzoic acid are dissolved in 40 mL MeOH and 1.8 mL (24.8 mmol, 1.14 eq) thionyl chloride are slowly added dropwise. The mixture is refluxed for 2 h at 50° C. and stirred for another 2 h. After cooling the volatile constituents are eliminated in vacuo and 4.36 g of the crude methyl 2-hydroxy-4-nitro-benzoate are obtained, which are reacted without further purification. 1 g (5.1 mmol, 1 eq) of the methyl ester are dissolved in 25 mL DMF, 2.1 g (15.3 mmol, 3 eq) potassium carbonate are added and then 1.4 mL (18.8 mmol, 3.7 eq) bromoethane are added dropwise. The reaction mixture is stirred for 16 h at RT, then poured into 100 mL water and the pH is adjusted with concentrated aqueous hydrochloric acid to pH 3. It is extracted twice with 100 mL EE, dried on MgSO4 and after the elimination of all the volatile constituents in vacuo 1.28 g of methyl 2-ethoxy-4-nitro-benzoate are obtained. 1.28 g (5.06 mmol, 1 eq) of the nitro compound are dissolved in 50 mL MeOH, a spatula tip of Raney nickel is added and the reaction mixture is stirred in the autoclave under a hydrogen pressure of 4 bar for 16 h. The catalyst is filtered off through Celite® and the filtrate is freed in vacuo of all the volatile constituents. 0.99 g of the aniline are obtained [MS-ESI+: 351 (M+H)+].

Workup

  1. temperatureAfter cooling the volatile constituents
  2. customare obtained
  3. customwhich are reacted without further purification
  4. stirringThe reaction mixture is stirred for 16 h at RT
  5. extractionIt is extracted twice with 100 mL EE
  6. customdried on MgSO4

Sources & evidence

ORD record
ord-7ad552fd00d54d15b842f50b5836d461
Source dataset
uspto-grants-2014_01
Patent number
US08623887B2

Reaction notes

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