p-Toluenesulfonic acid → 4-methoxybenzyl (2RS)-2-hydroxy-2-[(3R,4R)-4-mercapto-3-phenylacetamidoazetidin-2-on-1-yl]acetate

HRID 376600Notes

Reaction equation

HRID 376600 reaction equation
C1(C)C=CC(S(O)(=O)=[O:8])=CC=1.[OH:12][CH:13]([N:26]1[C:32](=[O:33])[C@@H:31]2[C@H:27]1[S:28][C:29]([CH2:34][C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1)=[N:30]2)[C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][C:21]([O:24][CH3:25])=[CH:20][CH:19]=1)=[O:15]>O.ClCCl.CC(C)=O>[OH:12][CH:13]([N:26]1[C@H:27]([SH:28])[C@H:31]([NH:30][C:29](=[O:8])[CH2:34][C:35]2[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=2)[C:32]1=[O:33])[C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][C:21]([O:24][CH3:25])=[CH:20][CH:19]=1)=[O:15]

Participants

6

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 536561234-Methoxybenzyl (RS)-2-hydroxy-2-[(lR,5R)-3-benzyl-4-thia-2,6-diazabicyclo[3.2.0)hept-2-en-7-on-6-yl]acetate

Product 1

HCID 544549564-methoxybenzyl (2RS)-2-hydroxy-2-[(3R,4R)-4-mercapto-3-phenylacetamidoazetidin-2-on-1-yl]acetate

Reagents, catalysts & solvents 3

HCID 180AcetoneSolventHCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Procedure

Toluene-4-sulphonic acid (3.42g, 17.98mmol) in water (8ml) was added to a solution of 4-methoxybenzyl (2RS)-2-hydroxy-2-[(1R,5R)-3-benzyl-4-thia-2,6-diazabicyclo[3.2.0]hept-2-en-7-on-6-yl]acetate (4.12g, 10.0mmol) in dichloromethane (20ml) and acetone (20ml). After stirring for 2.5h at room temperature, the reaction mixture was diluted with dichloromethane, washed with water (x2), dried and concentrated in vacuo to yield crude 4-methoxybenzyl (2RS)-2-hydroxy-2-[(3R,4R)-4-mercapto-3-phenylacetamidoazetidin-2-on-1-yl]acetate as a colourless foam. The crude thiol was dissolved in acetone (50ml) and treated with a solution of 2-bromoacetyl-5-methyltetrahydrofuran (1.67g, 8.1mmol) in acetone (5ml). After 10 min., potassium carbonate (687mg, 5.0mmol) was added, and the mixture stirred for a further 30 min. The reaction mixture was diluted with ethyl acetate, washed successively with water (x2) and brine, dried and concentrated. The residue was purified by chromatography on silica gel eluting with 50, 70 and 80% ethyl acetate in hexane to yield the title compound as a colourless foam (2.68g, 60%); vmax (CH2Cl2) 3412, 1781, 1744, 1685 and 1515cm-1. (Mass spectrum: +ve ion (3-nitrobenzyl alcohol, sodium acetate) MNa+ (579)].

Workup

  1. washwashed with water (x2)
  2. customdried
  3. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-91cbdbfd55ee44b5bb14e0b3e32cc507
Source dataset
uspto-grants-2000_02
Patent number
US06020329

Reaction notes

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