Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (4S,5R)-N-(t-Butylaminocarbonyl)-2-(2,4-dimethoxyphenyl)-4-phenyl-5-oxazolidinecarboxylic acid methyl ester

HRID 1106987Notes

Reaction equation

HRID 1106987 reaction equation
[CH3:1][O:2][C:3](=[O:21])[CH:4]([OH:20])[CH:5]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)[NH:6][C:7]([NH:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8].CO[CH:24](OC)[C:25]1[CH:30]=[CH:29][C:28]([O:31][CH3:32])=[CH:27][C:26]=1[O:33][CH3:34].C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C1COCC1>[CH3:1][O:2][C:3]([C@@H:4]1[O:20][CH:24]([C:25]2[CH:30]=[CH:29][C:28]([O:31][CH3:32])=[CH:27][C:26]=2[O:33][CH3:34])[N:6]([C:7]([NH:9][C:10]([CH3:13])([CH3:11])[CH3:12])=[O:8])[C@H:5]1[C:14]1[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1)=[O:21]

Participants

5

Reactant 3

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 142873251-(Dimethoxymethyl)-2,4-dimethoxybenzeneHCID 22389502N-(t-butylaminocarbonyl)-beta-phenyl isoserine methyl ester

Product 1

HCID 53753692(4S,5R)-N-(t-Butylaminocarbonyl)-2-(2,4-dimethoxyphenyl)-4-phenyl-5-oxazolidinecarboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

N-(t-butylaminocarbonyl)-β-phenyl isoserine methyl ester (PREPARATION 1, 68 mg, 0.23 mM) is dissolved in dry THF (5 mL) and the solution treated with 2,4-dimethoxy benzaldehyde dimethyl acetal (70 mg, 0.33 mM) and pyridinium p-toluenesulfonate (6 mg, 0.02 mM) and the mixture warmed to reflux. Approximately 2 mL solvent is boiled away 3 times in a 45 minute period replenishing with 2 mL of fresh THF at which time TLC shows no starting material. The solvent is concentrated under reduced pressure and chromatographed (7 g of silica gel packed in ethyl acetate/1hexane, 1/3; elution with 80 mL ethyl acetate/hexane, 1/3; 45 mL ethyl acetate/hexane, 1/2; 30 mL ethyl acetate/hexane, 2/3 and 30 mL ethyl acetate/hexane, 1/1) to give the title compound: less polar isomer found in fractions 21-31--NMR (CDCl3, TMS) 1.19, 3.82, 3.85, 3.89, 4.68, 4.88, 5.52, 6.46, 6.70 and 7.25-7.50 δ, MS (FAB-High Res.) theory for C24H31N2O6 +H=443.2182, found=443.2172; more polar isomer in fractions 33-42--NMR (CDCl3, TMS) 0.99, 3.53, 3.81, 3.88, 4.05, 4.55, 5.45, 6.48, 6.79 and 7.25-7.50 δ; MS (FAB-High Res.) theory for C24H31N2O6 +H=443.2182, found=443.2180.

Workup

  1. temperaturethe mixture warmed to reflux
  2. customin a 45 minute
  3. concentrationThe solvent is concentrated under reduced pressure
  4. customchromatographed
  5. wash(7 g of silica gel packed in ethyl acetate/1hexane, 1/3; elution with 80 mL ethyl acetate/hexane, 1/3; 45 mL ethyl acetate/hexane, 1/2; 30 mL ethyl acetate/hexane, 2/3 and 30 mL ethyl acetate/hexane, 1/1)

Sources & evidence

ORD record
ord-6c902787c90440b19a9b0d7e728ff127
Source dataset
uspto-grants-2000_05
Patent number
US06057452

Reaction notes

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