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| | 4-Methyl-1,3-oxazole-5-carboxylic acid Basic information |
| | 4-Methyl-1,3-oxazole-5-carboxylic acid Chemical Properties |
| Melting point | 239 °C | | Boiling point | 267.3±20.0 °C(Predicted) | | density | 1.348±0.06 g/cm3(Predicted) | | storage temp. | Sealed in dry,Store in freezer, under -20°C | | pka | 2.09±0.31(Predicted) | | form | powder to crystal | | color | White to Gray to Brown | | InChI | 1S/C5H5NO3/c1-3-4(5(7)8)9-2-6-3/h2H,1H3,(H,7,8) | | InChIKey | ZIXUNDOOBLSXPE-UHFFFAOYSA-N | | SMILES | Cc1ncoc1C(O)=O | | CAS DataBase Reference | 2510-32-9 |
| Hazard Codes | Xi,Xn | | Risk Statements | 22-36/37/38 | | Safety Statements | 22-26-36/37/39 | | WGK Germany | 3 | | Hazard Note | Irritant | | HS Code | 29349990 | | Storage Class | 11 - Combustible Solids |
| | 4-Methyl-1,3-oxazole-5-carboxylic acid Usage And Synthesis |
| Chemical Properties | White to tan solid | | Uses | 4-Methoxyoxazole-5-carboxylic Acid is used in the synthesis of highly selective α4β2-Nicotinic acetylcholine receptor agonists used in the treatment of cognitive disorders. It is also used in the synthesis of small molecule human FPR1 receptor antagonists. | | Uses | Used in a palladium-catalyzed cross-coupling between heteroaryl carboxylic acids and aryl bromides leading to arylated heterocycles. | | Synthesis | The general procedure for the synthesis of 4-methyl-1,3-oxazole-5-carboxylic acid from the compound (CAS:77287-34-4) and ethyl 2-chloroacetoacetate is as follows:
1. ethyl 2-chloroacetoacetate (1 wt., 1 eq., 1000 g) was mixed with formamide (0.68 v/v, ca. 2.8 eq.), and the resulting solution was heated to 120° C. The reaction was carried out as follows.
2. After 5 hours of reaction, the mixture was cooled to room temperature and allowed to stand overnight under nitrogen protection.
3. the mixture was treated with 3M NaOH aqueous solution (6 vol.), the reaction was moderately exothermic and stirred for 4 hours at room temperature.
4. Add ethyl acetate (6 v/v) and separate the two phases. The organic layer was discarded and the aqueous phase was adjusted to pH 2 with 32% aqueous HCl (about 2.0 vol. portions required), at which point a precipitate began to form.
5. The suspension was treated with ethyl acetate (8 v/v) with vigorous stirring until most of the precipitate was dissolved.
6. The aqueous phase was further extracted twice with ethyl acetate (6 vol. parts each), the organic layers were combined and distilled to a small volume (the suspension was observed to reappear).
7. Fresh ethyl acetate (8 vol. parts) was added and the mixture was evaporated to dryness.
8. The collected solid was dried under reduced pressure at 40 °C overnight to afford 4-methyl-1,3-oxazole-5-carboxylic acid (498 g, 64.5% yield). | | References | [1] Patent: WO2005/80382, 2005, A1. Location in patent: Page/Page column 47-48
[2] Patent: WO2007/22933, 2007, A1. Location in patent: Page/Page column 31-32
[3] Patent: WO2007/22980, 2007, A1. Location in patent: Page/Page column 35; 36
[4] Patent: WO2005/123717, 2005, A1. Location in patent: Page/Page column 21-22
[5] Patent: WO2006/108700, 2006, A1. Location in patent: Page/Page column 34-35 |
| | 4-Methyl-1,3-oxazole-5-carboxylic acid Preparation Products And Raw materials |
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