Boron tribromide → Ethyl 2-(4-hydroxyphenyl)-4-methyl-1,3-thiazole-5-carboxylate

HRID 250228Notes

Reaction equation

HRID 250228 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[S:10][C:9]([C:11]2[CH:16]=[CH:15][C:14]([O:17]C)=[CH:13][CH:12]=2)=[N:8][C:7]=1[CH3:19])=[O:5])[CH3:2].B(Br)(Br)Br>ClCCl>[CH2:1]([O:3][C:4]([C:6]1[S:10][C:9]([C:11]2[CH:12]=[CH:13][C:14]([OH:17])=[CH:15][CH:16]=2)=[N:8][C:7]=1[CH3:19])=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 7540952Ethyl 2-(4-methoxyphenyl)-4-methyl-1,3-thiazole-5-carboxylate

Product 1

HCID 135509402Ethyl 2-(4-hydroxyphenyl)-4-methyl-1,3-thiazole-5-carboxylateYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a −80° C. solution of 2-(4-methoxy-phenyl)-4-methyl-thiazole-5-carboxylic acid ethyl ester (550 mg, 2 mmol) in dichloromethane (20 mL) is added BBr3 (5 mL, 1M solution in dichloromethane). The reaction is stirred at ambient temperature overnight. The reaction is quenched by addition of methanol and is concentrated in vacuo. The residue is partitioned between EtOAc and 1N HCl. The organic layer is concentrated and the residue is purified by chromatography (0 to 30% EtOAc in hexanes) to give the title compound as a tan solid, (500 mg, 95%). LC-ES/MS m/e 264 (M+1), 1H NMR (DMSO-d6) δ 10.22 (s, 1H), 7.82 (d, 2H), 6.86 (d, 2H), 4.27 (q, 2H), 2.64 (s, 3H), 1.29 (t, 3H).

Workup

  1. customThe reaction is quenched by addition of methanol
  2. concentrationis concentrated in vacuo
  3. customThe residue is partitioned between EtOAc and 1N HCl
  4. concentrationThe organic layer is concentrated
  5. customthe residue is purified by chromatography (0 to 30% EtOAc in hexanes)

Sources & evidence

ORD record
ord-9d782fffaabb4f549ad082d094bccbc4
Source dataset
uspto-grants-2011_01
Patent number
US07863302B2

Reaction notes

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