4-Methyl-5-(2-hydroxyethyl)thiazole → Triphenylphosphine Oxide

HRID 1373185Notes

Reaction equation

HRID 1373185 reaction equation
CC([O:4]C(/N=N/C(OC(C)C)=O)=O)C.CC1N=CSC=1CCO.[C:24]1([P:30]([C:37]2[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=2)[C:31]2[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=2)[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>C1COCC1>[C:37]1([P:30](=[O:4])([C:24]2[CH:25]=[CH:26][CH:27]=[CH:28][CH:29]=2)[C:31]2[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=2)[CH:38]=[CH:39][CH:40]=[CH:41][CH:42]=1

Participants

5

Reactant 3

HCID 11364-Methyl-5-(2-hydroxyethyl)thiazoleHCID 11776TriphenylphosphineHCID 5363146Diisopropyl azodicarboxylate

Product 1

HCID 13097Triphenylphosphine Oxide

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

DIAD (3.16 ml, 16.1 mM) was added to a stirred solution of methyl 3-nitro-5-hydroxy benzoate (2.11 g, 10.7 mM), 2-(4-methylthiazol-5-yl) ethanol (1.55 ml, 12.8 mM) and triphenylphosphine (4.21 g, 16.1 mM) in THF (50 ml) under an argon atmosphere at room temperature. After 1 hr reaction mixture concentrated in vacuo, and the residue triturated with diethyl ether to give a colourless solid (triphenylphosphine oxide). Diethyl ether conc. to give a dark brown gum, purification on silica gel (50% to 75% EtOAc/iso-hexane) gave the product contaminated with reduced DIAD and triphenylphosphine oxide (6.8 g). The crude product was dissolved/suspended in MeOH (80 ml), 2M NaOH (20 ml, 40 mM) added, heated at 65° C. for 4 hrs then cooled and concentrated. The residue was diluted with water (140 ml)/2M NaOH (40 ml), the precipitated triphenylphosphine oxide filtered, then acidified with c. HCl to pH=1–2. The precipitate was filtered, washed with water, dried under high-vacuum to give 3-nitro-5-(4-methyl-thiazol-5-yl) ethoxy] benzoic acid as a colourless solid (3.12 g, 79% over 2 steps); 1H NMR δ (d6-DMSO): 2.39 (s, 3H), 3.23 (t, 2H), 4.35 (t, 2H), 7.78 (s. 1H), 7.90 (m, 1H), 8.22 (s, 1H), 8.93 (s, 1H).

Workup

  1. customAfter 1 hr reaction mixture
  2. concentrationconcentrated in vacuo
  3. customthe residue triturated with diethyl ether

Sources & evidence

ORD record
ord-f57f538c18604857b0009b348b1c3857
Source dataset
uspto-grants-2007_01
Patent number
US07160906B2

Reaction notes

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