tert-Butanol → Ethyl 6-(tert-butoxycarbonylamino)-3-pyridazine carboxylate

HRID 1455988Notes

Reaction equation

HRID 1455988 reaction equation
Cl[C:2]1[N:7]=[N:6][C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:4][CH:3]=1.[N-:13]=[C:14]=[O:15].[K+].[C:17]([OH:21])([CH3:20])([CH3:19])[CH3:18].COCCOCCOC>CN(C=O)C.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[C:17]([O:21][C:14]([NH:13][C:2]1[N:7]=[N:6][C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:4][CH:3]=1)=[O:15])([CH3:20])([CH3:19])[CH3:18]

Participants

7

Reactant 4

HCID 6386tert-ButanolHCID 8150DiglymeHCID 10352425Ethyl 6-chloropyridazine-3-carboxylateHCID 11051572Potassio isocyanate

Product 1

HCID 22105617Ethyl 6-(tert-butoxycarbonylamino)-3-pyridazine carboxylate

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 6228DimethylformamideSolvent

Procedure

A mixture of ethyl 6-chloro-3-pyridazine carboxylate (6.5 g) [British patent number 856, 409], potassium isocyanate (3.5 g), tert-butanol (6.0 ml), tetrakis(triphenylphosphine)palladium (400 mg) and diglyme (6 ml) in DMF (50 ml) was heated at reflux for 2 hours, cooled and partitioned between diethyl ether and water. The organic layer was dried (MgSO4), filtered through silica gel and evaporated. The resulting solid was purified by crystallisation from iso-hexane to give ethyl 6-(tert-butoxycarbonylamino)-3-pyridazine carboxylate (2.4 g), mp 87°-88° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 2 hours
  3. temperaturecooled
  4. custompartitioned between diethyl ether and water
  5. dry with materialThe organic layer was dried (MgSO4)
  6. filtrationfiltered through silica gel
  7. customevaporated
  8. customThe resulting solid was purified by crystallisation from iso-hexane

Sources & evidence

ORD record
ord-cb5abc9447dc4bcd929602a6aed871a5
Source dataset
uspto-grants-1998_12
Patent number
US05843942

Reaction notes

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