Pyridine → Phenyl pyridazin-3-ylcarbamate

HRID 1666386Notes

Reaction equation

HRID 1666386 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([NH2:7])[N:2]=1.N1C=CC=CC=1.Cl[C:15]([O:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:16]>C1COCC1.CC#N>[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([NH:7][C:15](=[O:16])[O:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[N:2]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 15891Phenyl chloroformateHCID 230373Aminopyridazine

Product 1

HCID 20150036Phenyl pyridazin-3-ylcarbamateYield 70%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a suspension of pyridazin-3-amine (5 g, 50 mmol) in THF (50 mL) and CH3CN (70 mL) was added pyridine (5.10 mL, 63.1 mmol) followed by phenyl chloroformate (6.95 mL, 55.2 mmol) slowly. The reaction was stirred overnight. The reaction was filtered to remove the precipitate. The filtrate was concentrated and then taken up in CH2Cl2 which was washed with water. The organic layer was dried using SPE phase separators and concentrated. The residue was purified by silica gel column chromatography (0-5% MeOH/CH2Cl2). An undesired side product eluted first followed by the title compound which was concentrated to give a white solid (7.5 g, 70% yield). MS (APCI 10 V) AP+1 216.12; 1H NMR (400 MHz, DMSO-d6) δ ppm 7.20-7.24 (m, 2H) 7.25-7.28 (m, 1H) 7.39-7.44 (m, 2H) 7.64-7.69 (m, 1H) 8.05 (dd, 1H) 8.94 (dd, 1H) 11.34 (s, 1H).

Workup

  1. filtrationThe reaction was filtered
  2. customto remove the precipitate
  3. concentrationThe filtrate was concentrated
  4. washwas washed with water
  5. customThe organic layer was dried
  6. concentrationconcentrated
  7. customThe residue was purified by silica gel column chromatography (0-5% MeOH/CH2Cl2)
  8. washAn undesired side product eluted first
  9. concentrationwas concentrated

Sources & evidence

ORD record
ord-faaa975048c241f0a614826f59239f5e
Source dataset
uspto-grants-2011_10
Patent number
US08044052B2

Reaction notes

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