5-Amino-2-chloropyridine → 4-(6-Chloro3-pyridinylamino)-3-ethoxy-cyclobut-3-ene-1,2-dione

HRID 2299082Notes

Reaction equation

HRID 2299082 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]([Cl:8])=[N:6][CH:7]=1.[CH2:9]([O:11][C:12]1[C:13](=O)[C:14](=[O:19])[C:15]=1[O:16]CC)[CH3:10]>C(O)C>[Cl:8][C:5]1[N:6]=[CH:7][C:2]([NH:1][C:13]2[C:14](=[O:19])[C:15](=[O:16])[C:12]=2[O:11][CH2:9][CH3:10])=[CH:3][CH:4]=1

Participants

4

Reactant 2

HCID 793055-Amino-2-chloropyridineHCID 123228Diethyl squarate

Product 1

HCID 183797454-(6-Chloro3-pyridinylamino)-3-ethoxy-cyclobut-3-ene-1,2-dioneYield 43.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Conditions

Temperature
80 °C

Procedure

5-Amino-2-chloropyridine (2.32 g, 18.0 mmol) in ethanol (50 mL) was added to a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione 3.07 g, 18.0 mmol) in ethanol (200 mL) at 70° C. over a period of 6 hours. The mixture was then heated at 80° C. for an additional 18 hours, filtered, and the solvents removed in vacuo. The crude product was suspended in 10% EtOH/EtOAc (30 mL) and adsorbed onto silica gel (15 g). Purification by flash chromatography on silica gel (eluted with 5% EtOH/EtOAc) provided 1.98 g of the desired product as a pale yellow powder.

Workup

  1. filtrationfiltered
  2. customthe solvents removed in vacuo
  3. customPurification by flash chromatography on silica gel (eluted with 5% EtOH/EtOAc)

Sources & evidence

ORD record
ord-269d8302093747f387612239fedce57c
Source dataset
uspto-grants-2002_12
Patent number
US06495576B2

Reaction notes

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