Tert-butyl 4-(3,3-dibromoallyl)piperidine-1-carboxylate → Tert-butyl 4-(prop-2-yn-1-yl)piperidine-1-carboxylate

HRID 1386727Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][CH:11]([CH2:14][CH:15]=[C:16](Br)Br)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C([Li])CCC>C1COCC1>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][CH:11]([CH2:14][C:15]#[CH:16])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of 118 mg (0.31 mmol) of 1-(t-butoxycarbonyl)-4-(3,3-dibromoprop-2-enyl)piperidine (from EXAMPLE 74, Step A) in 4 mL of THF at −78° C. was added 0.370 mL (0.92 mmol) of a 2.5 M solution of butyllithium. After stirring at −78° C. for 45 min, the reaction mixture was quenched with 4 mL of sat'd NH4Cl and diluted with 25 mL of ether. After separating the phases, the aqueous layer was extracted with 25 mL of ether. The combined organic phases were washed with 50 mL of sat'd NaCl, dried over MgSO4 and concentrated. The residue was purified by flash chromatography eluting with 4:1 v/v hexanes/ether to give 55 mg (80%) of the title compound: 1H NMR (500 MHz) δ 1.18-1.26 (2H), 1.47 (s, 9H), 1.60-1.67 (m, 11), 1.77 (br d, J=13.2, 2H), 1.99 (t, J=2.6, 11H), 2.16 (dd, J=6.6, 2.5, 2H), 2.68-2.74 (2H), 4.12 (br d, J=13.0,22H).

Workup

customthe reaction mixture was quenched with 4 mL of sat'd NH4Cl
additiondiluted with 25 mL of ether
customAfter separating the phases
extractionthe aqueous layer was extracted with 25 mL of ether
washThe combined organic phases were washed with 50 mL of sat'd NaCl
dry with materialdried over MgSO4
concentrationconcentrated
customThe residue was purified by flash chromatography
washeluting with 4:1 v/v hexanes/ether

Sources & evidence

ORD record: ord-89669f099d3a48d08a99ba763dc93cea
Source dataset: uspto-grants-2001_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06265434B1

Reaction notes

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