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| | Ethyl 3-amino-4-pyrazolecarboxylate Basic information |
| | Ethyl 3-amino-4-pyrazolecarboxylate Chemical Properties |
| Melting point | 105-107 °C(lit.) | | Boiling point | 278.95°C (rough estimate) | | density | 1.3092 (rough estimate) | | refractive index | 1.6500 (estimate) | | storage temp. | 2-8°C | | solubility | Chloroform (Sparingly), Methanol (Slightly) | | form | Crystalline Powder | | pka | 12.98±0.50(Predicted) | | color | White to yellow | | BRN | 4964 | | Stability: | Light sensitive | | InChI | InChI=1S/C6H9N3O2/c1-2-11-6(10)4-3-8-9-5(4)7/h3H,2H2,1H3,(H3,7,8,9) | | InChIKey | YPXGHKWOJXQLQU-UHFFFAOYSA-N | | SMILES | N1C=C(C(OCC)=O)C(N)=N1 | | CAS DataBase Reference | 6994-25-8(CAS DataBase Reference) | | NIST Chemistry Reference | 3-Amino-4-carbethoxypyrazole(6994-25-8) |
| | Ethyl 3-amino-4-pyrazolecarboxylate Usage And Synthesis |
| Chemical Properties | Off-White Powder | | Uses | Ethyl 3-Amino-4-pyrazolecarboxylate (Allopurinol EP Impurity D) is an impurity of Allopurinol (A547300), a pyrazole derivative that has been shown to induce neoplasm immunogenicity. | | General Description | Pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards | | Synthesis | General procedure for the synthesis of ethyl 5-amino-1H-pyrazole-4-carboxylate from ethyl ethoxymethylcyanoacetate: ethyl ethoxymethylcyanoacetate (68 g, 0.4 mol) was added to a reaction vessel containing 200 mL of anhydrous ethanol; 100 mL of hydrazine hydrate was added slowly and dropwise to the reaction vessel. The reaction mixture was placed in an electric heating jacket and gradually heated up to 80 °C within 30 min to obtain mixture A. The mixture A was heated to reflux and kept in reflux reaction for 4 h. The reaction was carried out under reduced pressure. Upon completion of the reaction, ethanol was removed by distillation under reduced pressure and the remaining solid was concentrated by evaporation. The concentrated solid was cooled to room temperature and left to precipitate a light yellow solid, which was filtered, washed and dried to give the intermediate ethyl 5-amino-1H-pyrazole-4-carboxylate. Cold anhydrous ethanol was used for the washing process. The mass of the final product ethyl 5-amino-1H-pyrazole-4-carboxylate was 41.68 g and the yield was 66.78%. | | References | [1] Patent: CN105949202, 2016, A. Location in patent: Paragraph 0048-0053
[2] Patent: CN106008517, 2016, A. Location in patent: Paragraph 0048; 0049; 0050; 0051; 0052; 0053
[3] Patent: CN106008519, 2016, A. Location in patent: Paragraph 0048; 0049; 0050; 0051; 0052; 0053
[4] Patent: CN105949199, 2016, A. Location in patent: Paragraph 0047-0052
[5] Patent: CN105949200, 2016, A. Location in patent: Page/Page column 6; 7; 23 |
| | Ethyl 3-amino-4-pyrazolecarboxylate Preparation Products And Raw materials |
| Raw materials | Acetic acid-->Hydrazinium hydroxide solution-->Triethyl orthoformate-->Ethyl cyanoacetate-->HYDRAZINE-->Ethyl (ethoxymethylene)cyanoacetate-->N,N-Dimethylformamide dimethyl acetal-->Propanoic acid, 2-cyano-3-ethoxy-, ethyl ester-->2-Propenoic acid, 2-cyano-3-methoxy-, ethyl ester, (2Z)--->Ethanol | | Preparation Products | Allopurinol-->Ethyl 5,7-dichloropyrazolo[1,5-A]pyrimidine-3-carboxylate-->1-H-pyrazole-4-carboxylic acid,3-broMo,ethyl ester-->5-AMINO-4-CARBETHOXY-1-PHENYLPYRAZOLE-->ethyl 5-(4-bromophenyl)-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidine-3-carboxylate-->1H-Pyrazole-4-carboxylic acid, 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-, ethyl ester-->ETHYL 5-(4-FLUOROPHENYL)-7-(TRIFLUOROMETHYL)PYRAZOLO[1,5-A]PYRIMIDINE-3-CARBOXYLATE |
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