Acetic Anhydride → 3-(4-Methoxyphenyl)-6H-[2]benzopyrano[4,3-c]pyridazin-6-one

HRID 986748Notes

Reaction equation

HRID 986748 reaction equation
C(OC(=O)C)(=O)C.O[C:9]1[CH:14]=[C:13]([C:15]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=2)[N:12]=[N:11][C:10]=1[C:23]1[CH:31]=[CH:30][CH:29]=[CH:28][C:24]=1[C:25]([OH:27])=[O:26]>C1(C)C=CC=CC=1>[CH3:22][O:21][C:18]1[CH:19]=[CH:20][C:15]([C:13]2[N:12]=[N:11][C:10]3[C:23]4[CH:31]=[CH:30][CH:29]=[CH:28][C:24]=4[C:25](=[O:27])[O:26][C:9]=3[CH:14]=2)=[CH:16][CH:17]=1

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 178488704HCID 178488704, compound

Product 1

HCID 135266143-(4-Methoxyphenyl)-6H-[2]benzopyrano[4,3-c]pyridazin-6-oneYield 92%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Acetic acid anhydride (100 ml), 2-[4-hydroxy-6-(4-methoxyphenyl)-3-pyridaziny]benzoic acid (11 g, 0.0342 mol) and toluene (100 ml) are reacted in a 250 ml flask; oil bath about 130° C. When the reaction is completed, the mixture toluene/acetic acid is distilled off at 96-108° C. (about 100 ml/1.5 hours). The acetic acid anhydride is eliminated under vacuum, the residue is taken up with methylene chloride (250 ml), washed with 5% aqueous sodium bicarbonate and then with water up to neutrality. THe organic layer is oven dried, and concentrated to dryness to give 3-(4-methoxyphenyl)-6H-[2]-benzopyrano[4,3-c]pyridazin-6-one 230°-231° C. (9,8 g; Yield 92%).

Workup

  1. customabout 130° C
  2. distillationthe mixture toluene/acetic acid is distilled off at 96-108° C. (about 100 ml/1.5 hours)
  3. washwashed with 5% aqueous sodium bicarbonate
  4. customdried
  5. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-b3ff0ddfed2d4251a4fcd0830a75534b
Source dataset
uspto-grants-1987_12
Patent number
US04716159

Reaction notes

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