Ethyl 4-iodobenzoate → Ethyl 4-[(2,2,4,4-tetramethyl-thiochroman-6-yl)-ethynyl]benzoate

HRID 6562

Reaction equation

HRID 6562 reaction equation
[CH3:1][C:2]1([CH3:16])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][CH:6]=[C:7]([C:14]#[CH:15])[CH:8]=2)[S:3]1.I[C:18]1[CH:28]=[CH:27][C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:20][CH:19]=1>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([CH3:16])[CH2:11][C:10]([CH3:12])([CH3:13])[C:9]2[C:4](=[CH:5][CH:6]=[C:7]([C:14]#[C:15][C:18]3[CH:28]=[CH:27][C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:20][CH:19]=3)[CH:8]=2)[S:3]1

Participants

5

Reactant 2

HCID 142891Ethyl 4-iodobenzoate2×HCID 156611292,2,4,4-Tetramethyl-6-ethynylthiochroman2×

Product 1

HCID 15661159Ethyl 4-[(2,2,4,4-tetramethyl-thiochroman-6-yl)-ethynyl]benzoate

Reagents, catalysts & solvents 2

HCID 6102075Dichlorobis(triphenylphosphine)palladiumCatalystHCID 8471TriethylamineSolvent

Procedure

A solution of 110.7 mg (0.481 mmol) of 2,2,4,4,-tetramethyl-6-ethynylthiochroman (Compound 3) and 142.3 mg (0.516 mmol) of ethyl 4-iodobenzoate (Compound 97) in 2 ml of triethylamine was placed in a heavy walled glass tube and degassed under argon. The mixture was then treated with a finely ground mixture of 42 mg (0.221 mmol) of cuprous iodide and 63 mg (0.09 mmol) of bis (triphenylphosphine) palladium (II) chloride. The reaction mixture was degassed under argon again and the tube was sealed. The mixture was stirred at room temperature for 40 hours. The triethylamine was removed under vacuum and the residue purified by flash chromatography (silica, 3% ethyl acetate in hexanes) to give the title compound as a pale yellow solid. PMR (CDCl3): δ 1.37-1.42 (15H, m), 1.96 (2H, s), 4.38 (2H, q, J~7.0 Hz), 7.25 (1H, dd, J~8.2 Hz, 1.8 Hz), 7.33 (1H, d, J~1.8 Hz), 7.37 (1H, d, J~8.2 Hz), 7.65 (2H, d, J~8.6 Hz), 8.01 (2H, d, J~8.6 Hz). MS exact mass, m/e 378.1636 (calcd. for C24H26O2S, 378.165.3).

Workup

  1. customdegassed under argon
  2. customThe reaction mixture was degassed under argon again
  3. customthe tube was sealed
  4. customThe triethylamine was removed under vacuum
  5. customthe residue purified by flash chromatography (silica, 3% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-91b8bb89ed7c42379155d02f724bb0c7
Source dataset
uspto-grants-1993_09
Patent number
US05248777

Linked notes

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