Ethyl 4-iodobenzoate → Ethyl 4-[(2,2,4,4,7-pentamethylchroman-6-yl)-ethynyl]benzoate

HRID 344963Notes

Reaction equation

HRID 344963 reaction equation
[CH3:1][C:2]1([CH3:17])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][C:6]([CH3:16])=[C:7]([C:14]#[CH:15])[CH:8]=2)[O:3]1.[CH2:18]([O:20][C:21](=[O:29])[C:22]1[CH:27]=[CH:26][C:25](I)=[CH:24][CH:23]=1)[CH3:19]>C(N(CC)CC)C.[Pd](Cl)Cl.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:1][C:2]1([CH3:17])[CH2:11][C:10]([CH3:12])([CH3:13])[C:9]2[C:4](=[CH:5][C:6]([CH3:16])=[C:7]([C:14]#[C:15][C:25]3[CH:26]=[CH:27][C:22]([C:21]([O:20][CH2:18][CH3:19])=[O:29])=[CH:23][CH:24]=3)[CH:8]=2)[O:3]1

Participants

5

Reactant 2

HCID 142891Ethyl 4-iodobenzoateHCID 156611392,2,4,4,7-Pentamethyl-6-ethynyl-chroman2×

Product 1

HCID 15661157Ethyl 4-[(2,2,4,4,7-pentamethylchroman-6-yl)-ethynyl]benzoate

Reagents, catalysts & solvents 2

HCID 6102075Dichlorobis(triphenylphosphine)palladiumCatalystHCID 8471TriethylamineSolvent

Conditions

Temperature
55 °C

Procedure

Nitrogen was bubbled for 15 min through a solution of 200 (0.877 mmol) of 2,2,4,4,7-pentamethyl-6-ethynylchroman (Compound 9) and 245.3 mg (0.888 mmol) of ethyl 4-iodobenzonate (Compound 97) in 2 ml of triethylamine. The mixture was then placed under an argon atmosphere and treated with a finely ground mixture of 50 mg (0.2625 mmol) of cuprous iodide and 100 mg (0.1425 mmol) of bis(triphenylphosphine) palladium (II) chloride. The reaction vessel was then fitted with a reflux condenser and the mixture was heated at 55 degrees C. under argon for 72 hours. The triethylamine was then removed under vacuum and the residue purified by flash chromatography (silica, 5% ethyl acetate in hexane) to give the title compound as a yellow oil. PMR (CDCl3) : & 1.32 (12H, s), 1.37 (3H, t, J~7.0 Hz), 1.80 (2H, s) 2.40 (3H, s), 4.36 (2H, q, J~7.0 Hz), 6.66 (1H, s, 7.42 (1H, s), 7.54 (2H, d, J~8.6 Hz), 7.99 (2H, d, J~8.6 Hz). MS exact mass, m/e 376.2 038 (calcd. for C25H28O3, 376 2038).

Workup

  1. customThe reaction vessel was then fitted with a reflux condenser
  2. customThe triethylamine was then removed under vacuum
  3. customthe residue purified by flash chromatography (silica, 5% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-1283888f52254228b822976c0b66b2f6
Source dataset
uspto-grants-1991_10
Patent number
US05053523

Reaction notes

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