Cesium carbonate → 2-(4-{2-[2-(4-Bromophenyl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methylpropionic acid ethyl ester

HRID 898435Notes

Reaction equation

HRID 898435 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[O:9][C:10]([CH3:26])=[C:11]([CH2:13][CH2:14][O:15]S(C3C=CC(C)=CC=3)(=O)=O)[N:12]=2)=[CH:4][CH:3]=1.[CH2:27]([O:29][C:30](=[O:42])[C:31]([O:34][C:35]1[CH:40]=[CH:39][C:38](O)=[CH:37][CH:36]=1)([CH3:33])[CH3:32])[CH3:28].C([O-])([O-])=O.[Cs+].[Cs+]>CN(C=O)C>[CH2:27]([O:29][C:30](=[O:42])[C:31]([O:34][C:35]1[CH:40]=[CH:39][C:38]([O:15][CH2:14][CH2:13][C:11]2[N:12]=[C:8]([C:5]3[CH:4]=[CH:3][C:2]([Br:1])=[CH:7][CH:6]=3)[O:9][C:10]=2[CH3:26])=[CH:37][CH:36]=1)([CH3:33])[CH3:32])[CH3:28]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 181741Ethyl 2-(4-hydroxyphenoxy)-2-methylpropanoateHCID 58979135Toluene-4-sulfonic acid 2-[2-(4-bromophenyl)-5-methyloxazol-4-yl]ethyl ester

Product 1

HCID 110273422-(4-{2-[2-(4-Bromophenyl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methylpropionic acid ethyl esterYield 44%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of toluene-4-sulfonic acid 2-[2-(4-bromophenyl)-5-methyloxazol-4-yl]ethyl ester (prepared as described in E above), 2-(4-hydroxyphenoxy)-2-methylpropanoic acid ethyl ester (American Home Products U.S. Pat. No. 3,795,691) (7.06 g, 31.5 mmol) and Cs2CO3 (13.3 g, 41.0 mmol) was heated at 55° C. in DMF (45 mL) for 18 h. The reaction was partitioned between EtOAc (250 mL) and H2O (250 mL), and the aqueous phase extracted with EtOAc (2×100 mL). The combined organic phases were dried (MgSO4) and concentrated under reduced pressure to an oil which was purified by column chromatography (1500 mL SiO2, hexanes to 10% EtOAc/hexanes) to provide 2-(4-{2-[2-(4-Bromophenyl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methyl propionic acid ethyl ester (6.81 g, 44%) as a off-white solid: Rf=0.48 in 35% EtOAc/hexanes; mp 78-79° C.; 1H NMR (300 MHz, CDCl3) δ 7.85-7.82 (m, 2H), 7.57-7.53 (m, 2H), 6.83-6.75 (m, 4H), 4.22 (q, J=7.0 Hz, 2H), 4.18 (t, J=6.6 Hz, 2H), 2.94 (t, J=6.7 Hz, 2H), 2.36 (s, 3H), 1.52 (s, 6H), 1.27 (t, J=7.0 Hz, 3H) and by-product 2-(4-Bromophenyl)-5-methyl-4-vinyloxazole (1.81 g, 22%) as a white solid: 1H NMR (300 MHz, CDCl3) δ 7.92-7.87 (m, 2H), 7.58-7.55 (m, 2H), 6.54 (dd, J=17.3, 10.8 Hz, 1H), 5.94 (dd, J=17.0, 1.8 Hz, 1H), 5.30 (dd, J=10.8, 1.8 Hz, 1H), 2.41 (s, 3H).

Workup

  1. customThe reaction was partitioned between EtOAc (250 mL) and H2O (250 mL)
  2. extractionthe aqueous phase extracted with EtOAc (2×100 mL)
  3. dry with materialThe combined organic phases were dried (MgSO4)
  4. concentrationconcentrated under reduced pressure to an oil which
  5. customwas purified by column chromatography (1500 mL SiO2, hexanes to 10% EtOAc/hexanes)

Sources & evidence

ORD record
ord-eb36b3d2ef9643e3bfb1d6608845e39c
Source dataset
uspto-grants-2008_04
Patent number
US07351728B2

Reaction notes

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