Dimethylformamide → 5-methyl-6-(2-thiophen-2-yl-benzoxazol-6-yl)-4,5-dihydro-2H-pyridazin-3-one

HRID 1619974Notes

Reaction equation

HRID 1619974 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([OH:8])=O.C(N1C=CN=C1)(N1C=CN=C1)=O.CN(C=O)C.[NH2:26][C:27]1[CH:32]=[CH:31][C:30]([C:33]2[CH:34]([CH3:40])[CH2:35][C:36](=[O:39])[NH:37][N:38]=2)=[CH:29][C:28]=1O>O.C(O)(=O)C>[CH3:40][CH:34]1[C:33]([C:30]2[CH:31]=[CH:32][C:27]3[N:26]=[C:6]([C:2]4[S:1][CH:5]=[CH:4][CH:3]=4)[O:8][C:28]=3[CH:29]=2)=[N:38][NH:37][C:36](=[O:39])[CH2:35]1

Participants

7

Reactant 4

HCID 6228DimethylformamideHCID 107002-Thiophenecarboxylic acidHCID 682631,1'-CarbonyldiimidazoleHCID 179934936-(4-amino-3-hydroxy-phenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one

Product 1

HCID 674612285-methyl-6-(2-thiophen-2-yl-benzoxazol-6-yl)-4,5-dihydro-2H-pyridazin-3-one

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

2.6 g (0.02 mol) thiophene-2-carboxylic acid, 3.3 g (0.02 mol) 1,1′carbonyldiimidazole and 50 ml DMF are combined and the mixture is stirred for 30 min at RT, then 4.4 g (0.02 mol) 6-(4-amino-3-hydroxy-phenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one are added and the mixture is stirred for 4 h at 60° C. The reaction mixture is diluted with water and acidified with glacial acetic acid, the precipitated solid is filtered off, washed with water and isopropanol and then dried. The solid obtained is heated to 130° C. with 60 g polyphosphoric acid for 30 min, then poured onto ice water and then extracted with chloroform. The org. phase is washed with water, dried on magnesium sulphate and the solv. is eliminated by rotary evaporation i.V. The residue is stirred with acetone/diethyl ether, filtered off and then recrystallised from isopropanol/dioxane.

Workup

  1. stirringthe mixture is stirred for 4 h at 60° C
  2. filtrationthe precipitated solid is filtered off
  3. washwashed with water and isopropanol
  4. customdried
  5. customThe solid obtained
  6. additionpoured onto ice water
  7. extractionextracted with chloroform
  8. washphase is washed with water
  9. customdried on magnesium sulphate
  10. stirringThe residue is stirred with acetone/diethyl ether
  11. filtrationfiltered off
  12. customrecrystallised from isopropanol/dioxane

Sources & evidence

ORD record
ord-c60741fc395b43049fb22bcdd84eaf04
Source dataset
uspto-grants-2014_07
Patent number
US08772323B2

Reaction notes

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