Ethanol → Ethyl 5,6-Dichloronicotinate

HRID 1908792Notes

Reaction equation

HRID 1908792 reaction equation
[Cl:1][C:2]1[C:3]([Cl:11])=[N:4][CH:5]=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8].[C:12]1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=C[CH:13]=1.C(O)C.CCOC(/N=N/C(OCC)=O)=O.C([O-])(O)=O.[Na+]>C1COCC1>[CH2:12]([O:8][C:7](=[O:9])[C:6]1[CH:10]=[C:2]([Cl:1])[C:3]([Cl:11])=[N:4][CH:5]=1)[CH3:13]

Participants

7

Reactant 5

HCID 702EthanolHCID 11776TriphenylphosphineHCID 2479875,6-Dichloronicotinic acidHCID 516892Sodium BicarbonateHCID 5462977Diethyl azodicarboxylate

Product 1

HCID 16762519Ethyl 5,6-DichloronicotinateYield 103.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5,6-dichloronicotinic acid (10.0 g, 50.0 mmol) in THF (600 mL), triphenylphosphine (19.67 g, 75.0 mmol) and ethanol (5.55 g, 75.0 mmol) is added. The mixture is cooled to 0° C. before DEAD (32.65 g, 75.0 mmol) is added. The mixture is stirred and warmed to rt. Stirring is continued for 16 h before sat. aq. NaHCO3 solution is added. The mixture is repeatedly extracted with EA. The combined org. extracts are dried over MgSO4, filtered and concentrated. The crude product is purified by CC (heptane:EA 7:3) to give 5,6-dichloronicotinic acid ethyl ester (11.4 g) as a white solid; LC-MS: tR=0.96 min, [M+1]+=220.02.

Workup

  1. additionis added
  2. stirringStirring
  3. additionis added
  4. extractionThe mixture is repeatedly extracted with EA
  5. dry with materialextracts are dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe crude product is purified by CC (heptane:EA 7:3)

Sources & evidence

ORD record
ord-c05430a0ac614db4bcd1c0dd635d6391
Source dataset
uspto-grants-2013_12
Patent number
US08598208B2

Reaction notes

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