2-(Tri-n-butylstannyl)oxazole → 5-Oxazol-2-yl-thiophene-3-carboxylic acid methyl ester

HRID 1914563Notes

Reaction equation

HRID 1914563 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:9]=[C:8](Br)[S:7][CH:6]=1)=[O:4].C([Sn](CCCC)(CCCC)[C:16]1[O:17][CH:18]=[CH:19][N:20]=1)CCC>C1(C)C=CC=CC=1.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.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.[Pd]>[CH3:1][O:2][C:3]([C:5]1[CH:9]=[C:8]([C:16]2[O:17][CH:18]=[CH:19][N:20]=2)[S:7][CH:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 154861832-(Tri-n-butylstannyl)oxazoleHCID 45873035Methyl 5-bromothiophene-3-carboxylate

Product 1

HCID 581103035-Oxazol-2-yl-thiophene-3-carboxylic acid methyl esterYield 37.2%

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

5-Bromo-thiophene-3-carboxylic acid methyl ester (0.3 g, 1.35 mmol) was dissolved in toluene (5 mL), 2-tributylstannyl oxazole (0.311 mL, 1.48 mmol) was added then the reaction mixture was purged with nitrogen before addition of palladium tetrakis(triphenylphosphine) (0.14 g, 0.12 mmol). The reaction mixture was heated at 100° C. over the weekend. The mixture was filtered then evaporated and the residue was purified by chromatography on a silica II cartridge, eluting with 10-20% DCM in pentane to give the title compound as a yellow solid (0.105 g). LCMS m/z 210 [M+H]+ and 251.23 [M+MeCN+H]+ R.T.=3.03 min (Analytical Method 6).

Workup

  1. filtrationThe mixture was filtered
  2. customthen evaporated
  3. customthe residue was purified by chromatography on a silica II cartridge
  4. washeluting with 10-20% DCM in pentane

Sources & evidence

ORD record
ord-d57adc78a892405b9a7f2472ae5cef31
Source dataset
uspto-grants-2013_12
Patent number
US08614209B2

Reaction notes

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