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Buchwald–Hartwig amination: 1-Bromo-4-phenylmethoxybenzene → (R)-4-(4-benzyloxyphenyl)-3-methylpiperazine-1-carboxylic acid tert-butyl ester

32% yield, run at 75 °C, as recorded by experimental reaction archive. The written procedure is below. One of 3 recorded runs making this product; all of them are compared below.

verified record, 32% yield recorded, Not balanced as written, From experimental reaction archive

Reagents, catalysts and solvents are in the table below.

The atoms, from reactants to products

CCCNCOOCCCCCCNCCCCOCCCCCCCCCBr
Reactants · 1/6
breakingformingbond order changesmapped atom that changes

Drawn from the record's atom map: which bonds break and which form between the reactants and products the source listed. It shows a change in connectivity, not a simulated trajectory and not a mechanism.

What was in the flask

RoleSpeciesFormulaYield
Reactant1-Bromo-4-phenylmethoxybenzeneC₁₃H₁₁BrO—
Reactant(R)-1-Boc-3-methylpiperazineC₁₀H₂₀N₂O₂—
Reagentpotassium 2-methylpropan-2-olateC₄H₉KO—
CatalystTris(1,1-dimethylethyl)phosphineC₁₂H₂₇P—
CatalystBis(tri-tert-butylphosphine)palladium(0)C₂₄H₅₄P₂Pd—
SolventTetrahydrofuranC₄H₈O—
Product(R)-4-(4-benzyloxyphenyl)-3-methylpiperazine-1-carboxylic acid tert-butyl esterC₂₃H₃₀N₂O₃31.55%

The equation does not balance as written. That is usual for an experimental record: the source listed what it put in and what it measured, not a stoichiometric equation.

Conditions

Temperature
75 °C

Only the dimensions the source stated are listed. Anything absent here was not recorded, and it is not inferred from what the class usually needs.

Yield

  • 32% of (R)-4-(4-benzyloxyphenyl)-3-methylpiperazine-1-carboxylic acid tert-butyl ester.

Every recorded run making this product

3 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.

CatalystReagentsSolventTemp.TimeYield
Tris(1,1-dimethylethyl)phosphine; Bis(tri-tert-butylphosphine)palladium(0)potassium 2-methylpropan-2-olateTetrahydrofuran75 °C—32% (this run)
Binap, (A+-)-; Palladium (II) acetatesodium 2-methylpropan-2-olateToluene150 °C—0%
1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine); Bis(dibenzylideneacetone)palladiumsodium 2-methylpropan-2-olateToluene150 °C—0%

Every value is as the source recorded it. A run with no yield was reported without one, and nothing here is averaged, modelled or filled in.

Procedure

Copied from the source record, unedited

A mixture of 1-(benzyloxy)-4-bromobenzene (789 mg, 3.00 mmol), (R)-tert-butyl 3-methylpiperazine-1-carboxylate (300 mg, 1.5 mmol), bis(tri-t- butylphosphine)palladium(0) (77 mg, 0.15 mmol) and potassium tert-butoxide (185 mg, 1.65 mmol) in THF (10 mL) was flushed with nitrogen and heated to 75 °C overnight. A further 0.1eq of bis(tri-t-butylphosphine)palladium(0) (77 mg, 0.15 mmol) was added and the reaction was heated for a further 2.5 hours. The solvent was evaporated and the residue dissolved in MeOH (10mL) and purified by ion exchange chromatography, using an SCX column. The desired product was eluted from the column using 0.35M NH3/MeOH and purified further by flash silica chromatography, elution gradient 0 to 20% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford

The source

This record comes from experimental reaction archive (ord-53993d3e76914a9480a25e3f9305c2e9). Open the source and check it against what is on this page.

  • experimental reaction archive record ord-53993d3e76914a9480a25e3f9305c2e9 from dataset "750 AstraZeneca ELN dataset" (url: https://chemrxiv.org/engage/chemrxiv/article-details/60c9e3f37792a23bfdb2d471). No atom mapping is provided by the source.

    experimental record · quality medium · source

experimental reaction record.

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.