tert-Butyl acetate → (S)-ethyl 2-(tert-butoxy)-2-(7-chloro-2-(3-chlorophenyl)-3,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)acetate

HRID 472883

Reaktionsgleichung

Reaktionsgleichung von HRID 472883
[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[C:14]([Cl:18])[CH:13]=3)[C:10]([CH3:11])=[C:6]2[N:5]=[C:4]([CH3:19])[C:3]=1[C@H:20]([OH:26])[C:21]([O:23][CH2:24][CH3:25])=[O:22].C(O[C:31]([CH3:34])([CH3:33])[CH3:32])(=O)C.Cl(O)(=O)(=O)=O>C(Cl)Cl>[C:31]([O:26][C@@H:20]([C:3]1[C:4]([CH3:19])=[N:5][C:6]2[N:7]([N:8]=[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[C:14]([Cl:18])[CH:13]=3)[C:10]=2[CH3:11])[C:2]=1[Cl:1])[C:21]([O:23][CH2:24][CH3:25])=[O:22])([CH3:34])([CH3:33])[CH3:32]

Komponenten

5

Edukt 3

HCID 10908tert-Butyl acetateHCID 24247Perchloric AcidHCID 86670293(S)-ethyl 2-(7-chloro-2-(3-chlorophenyl)-3,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate

Produkt 1

HCID 86670294(S)-ethyl 2-(tert-butoxy)-2-(7-chloro-2-(3-chlorophenyl)-3,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)acetateAusbeute 56,6 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel2×

Versuchsvorschrift

A solution of (S)-ethyl 2-(7-chloro-2-(3-chlorophenyl)-3,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (3.08 g, 7.81 mmol) in CH2Cl2 (130 ml) was treated with tert-butyl acetate (73.9 ml, 547 mmol) and perchloric acid (2.014 ml, 23.44 mmol), and the reaction was stoppered. The reaction was stirred for 2.5 hrs, then diluted with CH2Cl2 (130 ml) and carefully quenched with sat. NaHCO3 (100 mL). The organic layer was separated and washed with brine (100 mL), dried (Na2SO4), filtered and concentrated to give a light amber mobile oil. The crude product was purified by flash silica gel column chromatography, eluting with 10%-30% EtOAc in hexanes, to afford the product, (S)-ethyl 2-(tert-butoxy)-2-(7-chloro-2-(3-chlorophenyl)-3,5-dimethylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (2.05 g, 4.42 mmol, 56.5% yield) as a viscous oil, which began to crystallize upon standing. 1H NMR (500 MHz, CDCl3) δ: 7.87 (t, J=1.5 Hz, 1H), 7.74 (dt, J=7.3, 1.5 Hz, 1H), 7.46-7.36 (m, 2H), 5.63 (s, 1H), 4.19 (q, J=7.0 Hz, 2H), 2.68 (s, 3H), 2.51 (s, 3H), 1.26 (s, 9H), 1.21 (t, J=7.0 Hz, 3H).

Aufarbeitung

  1. customcarefully quenched with sat. NaHCO3 (100 mL)
  2. customThe organic layer was separated
  3. washwashed with brine (100 mL)
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give a light amber mobile oil
  8. customThe crude product was purified by flash silica gel column chromatography
  9. washeluting with 10%-30% EtOAc in hexanes

Quellen und Nachweise

ORD-Eintrag
ord-1bbe6e907cdb45b2a00d8b2af05a970e
Quelldatensatz
uspto-grants-2014_01
Patentnummer
US08633200B2

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