Sodium hydride → Ethyl 2-(5-ethyl-2-pyridyl)-4-isopropyl-4-methyl-5-oxo-2-imidazoline-1-crotonate

HRID 2393774Notes

Reaction equation

HRID 2393774 reaction equation
[H-].[Na+].[CH2:3]([C:5]1[CH:6]=[CH:7][C:8]([C:11]2[NH:12][C:13](=[O:20])[C:14]([CH:17]([CH3:19])[CH3:18])([CH3:16])[N:15]=2)=[N:9][CH:10]=1)[CH3:4].Br[CH2:22]/[CH:23]=[CH:24]/[C:25]([O:27][CH2:28][CH3:29])=[O:26]>O1CCCC1>[CH2:3]([C:5]1[CH:6]=[CH:7][C:8]([C:11]2[N:12]([CH2:22]/[CH:23]=[CH:24]/[C:25]([O:27][CH2:28][CH3:29])=[O:26])[C:13](=[O:20])[C:14]([CH:17]([CH3:19])[CH3:18])([CH3:16])[N:15]=2)=[N:9][CH:10]=1)[CH3:4]

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 5373944Ethyl (E)-4-bromobut-2-enoateHCID 133398183-Descarboxy Imazethapyr

Product 1

HCID 22450183Ethyl 2-(5-ethyl-2-pyridyl)-4-isopropyl-4-methyl-5-oxo-2-imidazoline-1-crotonateYield 25.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A stirred suspension of sodium hydride (1.6 g, 53 mmol, 80% oil dispersion) in dry tetrahydrofuran is treated with a solution of 2-(5-ethyl-2-pyridyl)-4-isopropyl-4-methyl-5-oxo-2-imidazoline (10.24 g, 41.80 mmol) in dry tetrahydrofuran dropwise via addition funnel. After addition is complete and effervescence subsides, ethyl 4-bromocrotonate (12.9 g, 50.1 mmol, 75% technical grade) is added to the reaction mixture at once. The resulting mixture is stirred at room temperature under nitrogen for 19 hours. After this period, the reaction mixture is partitioned between water and ether. The layers are separated, and the organic layer is dried over magnesium sulfate, decolorized with activated charcoal, vacuum filtered through diatomaceous earth, and concentrated in vacuo to obtain a dark brown oil. The oil is purified by flash chromatography (2:1 hexanes/ethyl acetate eluent) to give the title product as a pale orange oil (3.78 g, 25%).

Workup

  1. additionAfter addition
  2. waitAfter this period
  3. customthe reaction mixture is partitioned between water and ether
  4. customThe layers are separated
  5. dry with materialthe organic layer is dried over magnesium sulfate
  6. filtrationfiltered through diatomaceous earth
  7. concentrationconcentrated in vacuo
  8. customto obtain a dark brown oil
  9. customThe oil is purified by flash chromatography (2:1 hexanes/ethyl acetate eluent)

Sources & evidence

ORD record
ord-34b33879558b4fc2a2d8dce5d5aec380
Source dataset
uspto-grants-1998_09
Patent number
US05808079

Reaction notes

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