Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Acetic Acid | HCID 176 | — |
| Reactant | 2-Hydrazinopyridine | HCID 78645 | — |
| Reactant | 3-Thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl ester | HCID 98424 | — |
| Reactant | Sodium | HCID 5360545 | — |
| Solvent | Methanol | HCID 887 | — |
| Solvent | Water | HCID 962 | — |
| Product | HCID 46244244 | HCID 46244244 | 56% |
Reaction Steps
A mixture of 7 g (64.1 mmol) of 2-hydrazinopyridine and 10.3 g (64.1 mmol) of methyl 4-oxotetrahydrothiophene-3-carboxylate in 130 mL of MeOH is heated for 12 hours at 80° C. The medium is then concentrated under reduced pressure and the residue obtained is purified by chromatography on a column of silica gel, eluting with a DCM/MeOH gradient of from 0 to 10% MeOH. After concentrating under reduced pressure, 8.7 g (34.5 mmol) of hydrazone intermediate, in the form of a yellow powder, are isolated and are then added portionwise, at room temperature, to a solution of 0.8 g (34.5 mmol) of sodium in 46 mL of anhydrous MeOH. The reaction medium is stirred for 2 hours at room temperature, and the precipitate formed is then filtered off and washed successively with 10 mL of MeOH and 20 mL of pentane. The residue obtained is dissolved in 20 mL of water and 10 mL of acetic acid are added. The precipitate obtained is filtered off, washed with 10 mL of water, dried under vacuum and recrystallized from EtOH. 4.2 g of 2-pyridin-2-yl-1,2,4,6-tetrahydro-3H-thieno[3,4-c]pyrazol-3-one are obtained in the form of a whitish powder.
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US09359329B2 |
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| Source dataset | uspto-grants-2016_06 |
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| ORD ID | ord-283afc56206447eea48df19a13f7103e |
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| Source note | uspto-grants-2016_06 |
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