L-(+)-Cysteine → 4-Methoxybenzaldehyde

HRID 2219790Notes

Reaction equation

HRID 2219790 reaction equation
O.Cl.[NH2:3][C@H:4]([C:7]([OH:9])=[O:8])[CH2:5][SH:6].C([O-])(=O)C.[Na+].N[C@H](C(O)=O)CS.[CH3:22][O:23][C:24]1[CH:31]=[CH:30][C:27]([CH:28]=[O:29])=[CH:26][CH:25]=1>C(O)C.O>[CH3:22][O:23][C:24]1[CH:31]=[CH:30][C:27]([CH:28]=[O:29])=[CH:26][CH:25]=1.[CH3:22][O:23][C:24]1[CH:31]=[CH:30][C:27]([CH:28]2[NH:3][CH:4]([C:7]([OH:9])=[O:8])[CH2:5][S:6]2)=[CH:26][CH:25]=1

Participants

8

Reactant 4

HCID 5862L-(+)-CysteineHCID 23462L-Cysteine hydrochloride monohydrateHCID 312444-MethoxybenzaldehydeHCID 517045Sodium Acetate

Product 2

HCID 312444-MethoxybenzaldehydeHCID 28277282-(4-Methoxy-phenyl)-thiazolidine-4-carboxylic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent3×HCID 962WaterSolvent

Procedure

A 22 L three-necked round bottom flask fitted with an internal temperature probe and a mechanical stirrer was charged with L-cysteine hydrochloride monohydrate (500.0 g, 2.85 mol), sodium acetate (260.0 g, 3.17 mol) and 4.00 L of water. The mixture was stirred until all of the L-cysteine dissolved. A solution of p-methoxybenzaldehyde (426.0 g, 3.13 mol) in 3.50 L of ethanol was prepared and added to the reaction such that the internal reaction temperature was kept below 30° C. The reaction becomes a thick white slurry during the addition of the p-methoxybenzaldehyde solution. After 30 minutes, 3.50 L of ethanol was added to the reaction. Stirring was continued for 1 hour and then the solid was isolated by filtration. A 1.50 L portion of ethanol was used to wash the solid. The solid was dried in a vacuum oven at 50° C. for 48 hours. Approximately 610 g of 2-(4-methoxy-phenyl)thiazolidine-4-carboxylic acid was obtained (90% yield). 1H NMR (300 MHz, DMSO) δ 7.41-7.31 (m, 4H), 6.93-6.83 (m, 4H), 5.56 (s, 1H), 5.42 (s, 1H), 4.23 (dd, J=6.7, 4.4 Hz, 1H), 3.84 (dd, J=7.6, 7.1 Hz, 1H), 3.73 (s, 3H), 3.71 (s, 3H), 3.37-3.23 (m, 2H), 3.16-3.00 (m, 2H).

Workup

  1. customA 22 L three-necked round bottom flask fitted with an internal temperature probe and a mechanical stirrer
  2. dissolutiondissolved
  3. additionadded to the reaction such that the internal reaction temperature
  4. customwas kept below 30° C
  5. waitwas continued for 1 hour
  6. customthe solid was isolated by filtration
  7. washto wash the solid
  8. customThe solid was dried in a vacuum oven at 50° C. for 48 hours

Sources & evidence

ORD record
ord-b4c7f575b962453295911a4493c278cc
Source dataset
uspto-grants-2008_08
Patent number
US07414137B2

Reaction notes

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