Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Sodium Hydroxide | HCID 14798 | — |
| Reactant | Phosphorus oxychloride | HCID 24813 | — |
| Reactant | Ethyl 2-aminopyridine-4-carboxylate | HCID 7015521 | — |
| Solvent | Ethanol | HCID 702 | — |
| Product | HCID 20568844 | HCID 20568844 | 42% |
Reaction Steps
0.02 moles of 2-amino-4-ethoxycarbonylpyridine and 0.02 moles of ethyl-2-ethylacetacetate are stirred in a mixture of 10 ml. of phosphorous oxychloride and 2 g. of polyphosphoric acid at 120° C. for 2 hours. The reaction mixture is treated with 20 ml. of ethanol at 70° to 80° C., whereupon it is neutralized with a 10% (w/v) aqueous sodium hydroxide solution with ice cooling. The ethanol is evaporated, the residue is extracted with four 25-ml. portions of chloroform and the combined extracts are dried and evaporated. The evaporation residue is triturated with ether to give crystalline 2-methyl-3-ethyl-8-ethoxycarbonyl-4-oxo-4H-pyrido-(1,2-a)pyrimidine, melting at 95° to 96° C. Yield 42%. The product does not give any melting point depression when admixed with the product of Example 17.
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US04291036 |
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| Source dataset | uspto-grants-1981_09 |
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| ORD ID | ord-83a59a18e0a745b48b046a8007b2ac9d |
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| Source note | uspto-grants-1981_09 |
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