HCID 20285482, compound → HCID 20285471, compound

HRID 127630Notes

Reaction equation

HRID 127630 reaction equation
C([O:5][C:6](=[O:22])[CH:7]([CH3:21])[N:8]([C:12](=[O:20])[CH:13]([CH3:19])[CH2:14][S:15][C:16](=[O:18])[CH3:17])[CH:9]1[CH2:11][CH2:10]1)(C)(C)C>C1(OC)C=CC=CC=1.FC(F)(F)C(O)=O>[C:16]([S:15][CH2:14][CH:13]([CH3:19])[C:12]([N:8]([CH:9]1[CH2:10][CH2:11]1)[CH:7]([C:6]([OH:22])=[O:5])[CH3:21])=[O:20])(=[O:18])[CH3:17]

Participants

4

Reactant 1

HCID 20285482HCID 20285482, compound

Product 1

HCID 20285471HCID 20285471, compoundYield 19.2%

Reagents, catalysts & solvents 2

HCID 6422Trifluoroacetic acidSolventHCID 7519AnisoleSolvent

Procedure

Crude N-(3-acetylthio-2-methylpropanoyl)-N-cyclopropyl-(dl)-alanine tert-butyl ester (60.2 g) was dissolved in a mixture of anisole (54 ml) and trifluoroacetic acid (96 ml). The resulting solution was stirred at room temperature for one hour. Trifluoroacetic acid was removed in vacuo and the residue was distributed between ethyl acetate and saturated sodium bicarbonate. The aqueous bicarbonate phase was separated and washed twice with ethyl acetate and then acidified to pH 4-5 with concentrated hydrocloric acid. The precipitated product was extracted into chloroform and washed twice with water. The organic phase was dried over magnesium sulfate, filtered and evaporated to give the crude acid as a thick yellow oil (22.9 g). The crude product was purified by HPLC, eluting with ethyl acetate/n-hexane/acetic acid (40:60:1), to give pure product as initially a pale yellow oil (9.6 g). The product was crystallized from ether/n-hexane to give colorless crystals, m.p. 83°-85° C.

Workup

  1. customTrifluoroacetic acid was removed in vacuo
  2. customThe aqueous bicarbonate phase was separated
  3. washwashed twice with ethyl acetate
  4. extractionThe precipitated product was extracted into chloroform
  5. washwashed twice with water
  6. dry with materialThe organic phase was dried over magnesium sulfate
  7. filtrationfiltered
  8. customevaporated
  9. customto give the crude acid as a thick yellow oil (22.9 g)
  10. customThe crude product was purified by HPLC
  11. washeluting with ethyl acetate/n-hexane/acetic acid (40:60:1)

Sources & evidence

ORD record
ord-80483e6fbd96482090057de28dc2ec55
Source dataset
uspto-grants-1981_03
Patent number
US04256761

Reaction notes

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