Buchwald–Hartwig amination: 2,4-Dichloropyridine → Ethyl 2-[(4-chloro-2-pyridinyl)amino]-1,3-oxazole-5-carboxylate
0% yield, run at 160 °C, as recorded by experimental reaction archive. The written procedure is below. One of 5 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 | Ethyl 2-amino-1,3-oxazole-5-carboxylate | C₆H₈N₂O₃ | |
| Reagent | Cesium carbonate | CCs₂O₃ | |
| Catalyst | Di-tert-butyl(2',4',6'-triisopropyl-3,6-dimethoxy-(1,1'-biphenyl)-2-yl)phosphine | C₃₁H₄₉O₂P | |
| Catalyst | Bis(dibenzylideneacetone)palladium | C₅₁H₄₂O₃Pd₂ | |
| Solvent | 1,4-Dioxane | C₄H₈O₂ | |
| Product | Ethyl 2-[(4-chloro-2-pyridinyl)amino]-1,3-oxazole-5-carboxylate | C₁₁H₁₀ClN₃O₃ | 0% |
Conditions
- Temperature
- 160 °C
Yield
- 0% of Ethyl 2-[(4-chloro-2-pyridinyl)amino]-1,3-oxazole-5-carboxylate.
Every recorded run making this product
5 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.
| Catalyst | Reagents | Solvent | Temp. | Time | Yield |
|---|---|---|---|---|---|
| 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 100 °C | — | 48% |
| 1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladium | Potassium Carbonate | Anisole | 90 °C | — | 0% |
| Di-tert-butyl(2',4',6'-tris(propan-2-yl)-(1,1'-biphenyl)-2-yl)phosphane; Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 160 °C | — | 0% |
| Di-tert-butyl(2',4',6'-triisopropyl-3,6-dimethoxy-(1,1'-biphenyl)-2-yl)phosphine; Bis(dibenzylideneacetone)palladium | Cesium carbonate | 1,4-Dioxane | 160 °C | — | 0% (this run) |
| 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 | 160 °C | — | 0% |
Procedure
Copied from the source record, unedited
Objective: Series of experiments to optimise yield of the above coupled product. Pd2(dba)3 (22.89 mg, 0.025 mmol), di-tert- butyl(2',4',6'-triisopropyl-3,6-dimethoxybiphenyl-2-yl)phosphine (48.4 mg, 0.10 mmol), 2,4-dichloropyridine (148 mg, 1.00 mmol), cesium carbonate (651 mg, 2.00 mmol),ethyl 2-aminooxazole-5-carboxylate (156 mg, 1.00 mmol) and 4,4'-di-tert-butylbiphenyl (60 mg, 0.23 mmol) were added to an oven dried microwave vial, the vial was capped and placed under an inert atmosphere, dioxane (4 mL) was added and the resulting mixture was heated at 160 °C for 1 h by microwave irradiation under a nitrogen atmosphere. Crude LCMS shows a switch in regioselectivity, with the other isomer becoming the major product in 25% yield based on internal standard (note: this is a rough estimate
The source
This record comes from experimental reaction archive (ord-81c9dfb0f9224007985242064ea9e33c). Open the source and check it against what is on this page.
experimental reaction archive record ord-81c9dfb0f9224007985242064ea9e33c 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
Other runs of this class, one page per distinct transformation.
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