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| | 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE Basic information |
| Product Name: | 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE | | Synonyms: | 7-dichloropyrazolo[1;5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE;Pyrazolo[1,5-a]pyrimidine, 5,7-dichloro-;o[1,5-a]pyrimidine;oropyrazoL;5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE CAS 57489-77-7 | | CAS: | 57489-77-7 | | MF: | C6H3Cl2N3 | | MW: | 188.01 | | EINECS: | | | Product Categories: | Heterocycle-Pyrimidine series;CHIRAL CHEMICALS | | Mol File: | 57489-77-7.mol | ![5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE Structure](CAS/GIF/57489-77-7.gif) |
| | 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE Chemical Properties |
| Melting point | 68-71 °C(Solv: ethanol (64-17-5)) | | density | 1.69±0.1 g/cm3(Predicted) | | storage temp. | under inert gas (nitrogen or Argon) at 2–8 °C | | pka | -1.68±0.30(Predicted) | | form | Solid | | color | Off-white to yellow | | InChI | InChI=1S/C6H3Cl2N3/c7-4-3-5(8)11-6(10-4)1-2-9-11/h1-3H | | InChIKey | JMTFWCYVZOFHLR-UHFFFAOYSA-N | | SMILES | C12=CC=NN1C(Cl)=CC(Cl)=N2 |
| | 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE Usage And Synthesis |
| Chemical Properties |
A yellow aromatic solid, incompatible with strong bases.
| | Uses | 5,7-Dichloropyrazolo[1,5-a]pyrimidine is a pharmaceutical intermediate compound that can be used in a palladium-catalysed pharmaceutical synthesis cross-coupling reaction. 2,4-Dichloroquinoline reacts with benzylzinc and phenylzinc reagents in the presence of catalytic quantities of palladium complexes to yield only α-substituted products.2,4-Dichloroquinolines have been found to react with benzylzinc and phenylzinc reagents in catalytic amounts of palladium compounds to produce only α-substituted products. LiCl was found to be an effective additive for γ-selective coupling reactions. These α- or γ-selective coupling conditions are applicable to the reaction of 5,7-Dichloropyrazolo[1,5-a]pyrimidine and biphenylmethyl zinc reagents in the synthesis of angiotensin II receptor antagonists. This regioselectivity should be generally applicable to other α,γ-dichloropyrazine systems[1]. | | Hazard |
5,7-Dichloropyrazolo[1,5-a]pyrimidine is harmful if swallowed, it causes skin irritation and serious eye irritation.
| | Synthesis | The general procedure for the synthesis of 5,7-dichloropyrazolo[1,5-a]pyrimidines from 7-hydroxy[1,5-a]pyrimidin-5(4H)-ones was as follows: trichlorophosphorus oxychloride (POCl3, 130 mL) was added to a reaction vial containing pyrazolo[1,5-a]pyrimidine-5,7-diol (10 g, 66 mmol). After the resulting suspension was cooled to 0°C, N,N-dimethylaniline (23 mL, 179 mmol) was slowly added. After the reaction mixture was warmed up to room temperature, the reaction was heated at 60°C for 16 h under the protection of nitrogen (N2). After completion of the reaction, the mixture was cooled to room temperature and concentrated to give a brown viscous liquid. This liquid was slowly poured into ice water and allowed to gradually warm to room temperature. Subsequently, the pH of the mixture was adjusted with saturated sodium bicarbonate (NaHCO3) solution to 8. The organic layer was extracted with dichloromethane (CH2Cl2, 4 x 50 mL), and the organic phases were combined and dried over anhydrous magnesium sulfate (MgSO4). The dried organic phase was concentrated under reduced pressure to give a brown liquid. Finally, the target product, 5,7-dichloropyrazolo[1,5-a]pyrimidine (10.7 g, 86% yield), was obtained as a white crystalline solid by fast column chromatography with the eluent ratio varied from 1:1 (v/v) dichloromethane:hexane gradient to 2:1 (v/v) dichloromethane:hexane. Mass spectrometry (MS) analysis showed m/z 189.36 [M + 1]. | | References | [1] TAKESHI SHIOTA; Teruo Y. Regioselective Reactions of Organozinc Reagents with 2,4-Dichloroquinoline and 5,7-Dichloropyrazolo[1,5-a]pyrimidine[J]. ACS Applied Electronic Materials, 1999. DOI:10.1021/jo981423a. |
| | 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE Preparation Products And Raw materials |
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