Buchwald–Hartwig amination: 2,4-Dichloropyridine → N-(4-chloro-2-pyridinyl)-1,3-oxazol-2-amine
2% yield, run at 140 °C, as recorded by experimental reaction archive. The written procedure is below. One of 11 recorded runs making this product; all of them are compared below.
The atoms, from reactants to products
What was in the flask
| Role | Species | Formula | Yield |
|---|---|---|---|
| Reactant | 2,4-Dichloropyridine | C₅H₃Cl₂N | |
| Reactant | 2-Aminooxazole | C₃H₄N₂O | |
| Reagent | Cesium carbonate | CCs₂O₃ | |
| Catalyst | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine) | C₃₉H₃₂OP₂ | |
| Catalyst | Bis(dibenzylideneacetone)palladium | C₅₁H₄₂O₃Pd₂ | |
| Solvent | 1,4-Dioxane | C₄H₈O₂ | |
| Product | N-(4-chloro-2-pyridinyl)-1,3-oxazol-2-amine | C₈H₆ClN₃O | 2.02% |
Conditions
- Temperature
- 140 °C
Yield
- 2% of N-(4-chloro-2-pyridinyl)-1,3-oxazol-2-amine.
Every recorded run making this product
11 runs of this class made the same product and differed in what else was in the flask. They are listed from the highest yield down, with this page's run marked.
| Reactants | Catalyst | Reagents | Solvent | Temp. | Time | Yield |
|---|---|---|---|---|---|---|
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Potassium Carbonate | Anisole | 120 °C | — | 50% |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Palladium (II) acetate | Cesium carbonate | 1,4-Dioxane | 100 °C | — | 11% |
| 2-Bromo-4-chloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 140 °C | — | 8% |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Sodium hydride | 1,4-Dioxane | 140 °C | — | 3% |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | sodium phenoxide | 1,4-Dioxane | 80 °C | — | 3% |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 140 °C | — | 2% (this run) |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Palladium (II) acetate | Cesium carbonate | Dimethylacetamide | 100 °C | — | 2% |
| 2-Bromo-4-chloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | sodium phenoxide | 1,4-Dioxane | 170 °C | — | 1% |
| 2,4-Dichloropyridine; 2-Aminooxazole | Bis(3,5-bis(trifluoromethyl)phenyl)(3,6-dimethoxy-2',4',6'-tri(propan-2-yl)(1,1'-biphenyl)-2-yl)phosphane; Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 140 °C | — | 0% |
| 2,4-Dichloropyridine; 2-Aminooxazole | 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Potassium Phosphate, Tribasic | 1,4-Dioxane | 160 °C | — | 0% |
| 2,4-Dichloropyridine; 2-Aminooxazole | Binap, (A+-)-; Bis(dibenzylideneacetone)palladium | sodium 2-methylpropan-2-olate | Toluene | 100 °C | — | 0% |
Procedure
Copied from the source record, unedited
Objective: To isolate some of the required product to provide an analytical sample for a large catalyst screen. 2,4-dichloropyridine (0.109 mL, 1.01 mmol), oxazol-2-amine (85 mg, 1.01 mmol), TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (22.89 mg, 0.02 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (44.0 mg, 0.08 mmol) (Xantphos) and cesium carbonate (660 mg, 2.03 mmol) were added to a microwave vail and the vial was purged with nitrogen. Degassed dioxane (4 mL) was then added and the reaction mixture was heated to 140 °C for 1 h under microwave irradiation. LCMS of crude reaction mixture showed some of the required product was formed, however the LCMS using acidic modifier was somewhat misleading as a side- product co-elutes with the required product thus giving the impress
The source
This record comes from experimental reaction archive (ord-bc6c718e90df4b2591cc2506c375ce3f). Open the source and check it against what is on this page.
experimental reaction archive record ord-bc6c718e90df4b2591cc2506c375ce3f from dataset "750 AstraZeneca ELN dataset" (url: https://chemrxiv.org/engage/chemrxiv/article-details/60c9e3f37792a23bfdb2d471). No atom mapping is provided by the source.
How to read this record
This is one experiment, not a rule. It says that on one occasion these species were combined under these conditions and this came out. It does not say the reaction will give the same result on your substrate, and nothing on the page has been generalised into a claim that it would.
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Where to next
More Buchwald–Hartwig amination records
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