Triphenylphosphine → ethanethioic acid, S-[4-(tert-butyldimethylsilyloxy)benzyl] ester

HRID 1794058Notes

Reaction equation

HRID 1794058 reaction equation
C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C([O:29][CH2:30][CH3:31])=O)=NC(OCC)=O.[Si:32]([O:39][C:40]1[CH:47]=[CH:46][C:43]([CH2:44]O)=[CH:42][CH:41]=1)([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:34])[CH3:33].[S:48]1C=CC=C1CC(O)=O>C1COCC1>[C:30](=[O:29])([S:48][CH2:44][C:43]1[CH:46]=[CH:47][C:40]([O:39][Si:32]([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:34])[CH3:33])=[CH:41][CH:42]=1)[CH3:31]

Participants

6

Reactant 4

HCID 11776TriphenylphosphineHCID 159702-Thiopheneacetic acidHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 10014460(4-((Tert-butyldimethylsilyl)oxy)phenyl)methanol

Product 1

HCID 86759958ethanethioic acid, S-[4-(tert-butyldimethylsilyloxy)benzyl] esterYield 51.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To an efficiently stirred solution of triphenylphosphine (81 g, 309 mmol) in THF (200 mL) was added diethyl azodicarboxylate (62.5 g, 309 mmol) at 0° C. The mixture was stirred for 30 min, after which time a thick white precipitate was obtained. The crude 4-(tert-butydimethylsilyloxy)-benzyl alcohol (48 g) in THF (100 mL) and thiolacetic acid (36.1 g, 474 mmol) were added dropwise while the temperature was maintained below 10° C. The reaction was stirred overnight while keeping the internal temperature below 10° C. The solvent was removed in vacuo and the residue was purified by flash column chromatography [SiO2: isohexane-ethyl acetate (9:1)] to give the product as a viscous brown oil (30.7 g, 50%).

Workup

  1. customafter which time a thick white precipitate was obtained
  2. temperaturewas maintained below 10° C
  3. stirringThe reaction was stirred overnight
  4. customthe internal temperature below 10° C
  5. customThe solvent was removed in vacuo
  6. customthe residue was purified by flash column chromatography [SiO2: isohexane-ethyl acetate (9:1)]

Sources & evidence

ORD record
ord-e3f54f15c05740479f6e12ac7e888872
Source dataset
uspto-grants-2006_04
Patent number
US07022707B2

Reaction notes

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