Cornforth reagent → HCID 10287620, compound

HRID 1270210Notes

Reaction equation

HRID 1270210 reaction equation
[CH3:1][O:2][C:3](=[O:29])[C:4]1[CH:9]=[CH:8][C:7]([CH:10]([OH:28])[C:11]#[C:12][C:13]2[CH:18]=[C:17]([C:19]3[S:20][CH:21]=[CH:22][CH:23]=3)[C:16]([O:24][CH3:25])=[CH:15][C:14]=2[O:26][CH3:27])=[CH:6][CH:5]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[CH3:1][O:2][C:3](=[O:29])[C:4]1[CH:5]=[CH:6][C:7]([C:10](=[O:28])[C:11]#[C:12][C:13]2[CH:18]=[C:17]([C:19]3[S:20][CH:21]=[CH:22][CH:23]=3)[C:16]([O:24][CH3:25])=[CH:15][C:14]=2[O:26][CH3:27])=[CH:8][CH:9]=1

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 69492813HCID 69492813, compound

Product 1

HCID 10287620HCID 10287620, compoundYield 75.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-[3-(2,4-Dimethoxy-5-thiophen-2-yl-phenyl)-1-hydroxy-prop-2-ynyl]-benzoic acid methyl ester (2.0 g, 4.90 mmol) from Ex-1C was dissolved in dichloromethane (60 mL). Pyridinium dichromate (3.70 g, 9.8 mmol) was added and the resulting mixture was stirred at room temperature under nitrogen for 5 h. The reaction was then filtered through a pad of celite and concentrated under reduced pressure. Silica gel chromatography (dichloromethane/methanol, 30:1) gave 1.5 g (75%) of the desired 4-[3-(2,4-dimethoxy-5-thiophen-2-yl-phenyl)-propynoyl]-benzoic acid methyl ester as a yellow solid, m.p. 198–200° C. 1H-NMR (300 MHz, CDCl3) δ 8.38 (d, 2H, J=8.0 Hz), 8.17 (d, 2H, J=8.0 Hz), 0.88 (s, 1H), 7.41 (dd, 1H, J=3.7 and 1.6 Hz), 7.33 (dd, 1H, J=5.2 and 1.6 Hz), 7.09 (dd, 1H, J=5.2 and 3.7 Hz), 6.55 (s, 1H), 4.05 (s, 3H), 4.01 (s, 3H), 4.00 (s, 31H); EIMS m/z 406 (M+).

Workup

  1. filtrationThe reaction was then filtered through a pad of celite
  2. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-dee0159f7cb143f1ace42486d32c270a
Source dataset
uspto-grants-2007_04
Patent number
US07202247B2

Reaction notes

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