Buchwald–Hartwig amination: 2,4-Dichloropyridine → N-(4-chloro-2-pyridinyl)-1,3-oxazol-2-amine
2% yield, run at 100 °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 | Palladium (II) acetate | C₄H₈O₄Pd | |
| Solvent | Dimethylacetamide | C₄H₉NO | |
| Product | N-(4-chloro-2-pyridinyl)-1,3-oxazol-2-amine | C₈H₆ClN₃O | 1.97% |
Conditions
- Temperature
- 100 °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% |
| 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% (this run) |
| 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
oxazol-2-amine (85 mg, 1.01 mmol), 2,4-dichloropyridine (0.151 mL, 1.01 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (70.4 mg, 0.12 mmol) and cesium carbonate (660 mg, 2.03 mmol) were stirred in DMA (5 mL). The mixture was purged with nitrogen for 10 minutes. Palladium(II) acetate (22.76 mg, 0.10 mmol) was added and the mixture heated at 100 °C for 70h. The mixture was cooled, filtered and concentrated. The crude product was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5µ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% NH3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford N-(4-chloropyridin-2-yl)oxazol-2-amine (3.90 mg, 1.967 %).
The source
This record comes from experimental reaction archive (ord-1cd8c235ce4f4167a93c6067f176b339). Open the source and check it against what is on this page.
experimental reaction archive record ord-1cd8c235ce4f4167a93c6067f176b339 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.
The pathway is a separate question, kept on separate pages. A mechanism here is the canonical arrow pushing for a class, run on real structures and labelled rule-derived. It is not evidence, and this record is not a mechanism.
Where to next
More Buchwald–Hartwig amination records
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