p-Toluenesulfonic acid monohydrate → HCID 131719382, compound

HRID 1720987Notes

Reaction equation

HRID 1720987 reaction equation
CC([Si](C)(C)[O:6][CH2:7][CH2:8][C@@H:9]([C:21]([NH:23][C@H:24]([C:33]([O:35][CH3:36])=[O:34])[CH2:25][O:26][CH2:27][CH:28]([O:31][CH3:32])[O:29][CH3:30])=[O:22])[NH:10][C:11]([O:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:12])(C)C.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[CH3:32][O:31][CH:28]([O:29][CH3:30])[CH2:27][O:26][CH2:25][C@@H:24]([C:33]([O:35][CH3:36])=[O:34])[NH:23][C:21](=[O:22])[C@H:9]([CH2:8][CH2:7][OH:6])[NH:10][C:11]([O:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:12]

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 131719383HCID 131719383, compound

Product 1

HCID 131719382HCID 131719382, compoundYield 89.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

A solution of N-[O-[(1,1-dimethylethyl)dimethylsilyl]-N-[(phenylmethoxy)carbonyl]-L-homoseryl]-O-(2,2-dimethoxyethyl)-L-serine, methyl ester [5.56 g, 10 mmol, prepared as described in Example 10(h)] in methanol (65 ml) was cooled to 0° C. (ice salt bath), treated with p-toluenesulfonic acid monohydrate (386 mg, 2.0 mmol) and stirred at 0° C. for 1.5 hours. The reaction was quenched with sodium bicarbonate solution (198 mg. in 20 ml water), stirred for 5 minutes then evaporated to remove the methanol. The aqueous phase was extracted with ethyl acetate (2×200 ml) and the combined organic extract was washed with water (110 ml), 5% sodium bicarbonate (80 ml) and brine (80 ml), dried (anhydrous sodium sulfate), filtered, evaporated to dryness and dried in vacuo. The crude product was chromatographed on silica gel column (Merck), eluting the column with ethyl acetate:hexane (2:1) and ethyl acetate:methanol (98:2) to give 3.975 g of title product as a syrup. TLC (ethyl acetate:hexane, 4:1) Rf =0.17.

Workup

  1. customThe reaction was quenched with sodium bicarbonate solution (198 mg. in 20 ml water)
  2. stirringstirred for 5 minutes
  3. customthen evaporated
  4. customto remove the methanol
  5. extractionThe aqueous phase was extracted with ethyl acetate (2×200 ml)
  6. extractionthe combined organic extract
  7. washwas washed with water (110 ml), 5% sodium bicarbonate (80 ml) and brine (80 ml)
  8. dry with materialdried (anhydrous sodium sulfate)
  9. filtrationfiltered
  10. customevaporated to dryness
  11. customdried in vacuo
  12. customThe crude product was chromatographed on silica gel column (Merck)
  13. washeluting the column with ethyl acetate:hexane (2:1) and ethyl acetate:methanol (98:2)

Sources & evidence

ORD record
ord-1611bc2390354484846adec4d26e273d
Source dataset
uspto-grants-1996_04
Patent number
US05508272

Reaction notes

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