Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Hydrochloric Acid | HCID 313 | — |
| Reactant | Butyryl chloride | HCID 8855 | — |
| Reactant | 6-(4-Hydroxyphenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one | HCID 135542478 | — |
| Solvent | Pyridine | HCID 1049 | — |
| Product | HCID 15016405 | HCID 15016405 | 80% |
Reaction Steps
A 100 ml round-bottomed flash was charged with pyridine (30 ml) and 7.10 g (34.8 mmol) of (±)-4,5-dihydro-6-(4'-hydroxyphenyl))-5-methyl-3(2H)-pyridazinone from Example I, then cooled to 0° C. under an atmosphere of nitrogen. Butanoyl chloride (4.10 g, 38.3 mmol) was added dropwise to the solution via syringe. The reaction mixture was stirred for 30 min at 0° C., warmed to 23° C. over 15 min then poured into 1N aqueous hydrochloric acid (400 ml). The aqueous solution was extracted with EtOAc (2×200 ml). The combined EtOAc extracts were successively washed with 5% aqueous sodium bicarbonate solution (300 ml), saturated aqueous sodium chloride (200 ml), dried over anhydrous magnesium sulfate (5 g), filtered and concentrated in vacuo to provide 9.8 g of crude product as a solid. Recrystallization from ethyl acetae/hexanes (2:1, 35 ml) yielded 7.61 g (80%) of pure (±)-6-(4'-butanoyloxyphenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone as colorless needles, m.p. 112°-113° C.
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US05204463 |
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| Source dataset | uspto-grants-1993_04 |
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| ORD ID | ord-012b4b3bd8c2430a8db64574c6678396 |
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| Source note | uspto-grants-1993_04 |
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