Acetic Anhydride → 6-Acetoxy-5,6-dihydro-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran

HRID 1975068Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1975068
[OH:1][CH:2]1[C:7]([CH3:9])([CH3:8])[O:6][C:5]2[CH:10]=[CH:11][S:12][C:4]=2[CH:3]1[N:13]1[CH2:17][CH2:16][CH2:15][C:14]1=[O:18].[C:19](OC(=O)C)(=[O:21])[CH3:20]>Cl(O)(=O)(=O)=O>[C:19]([O:1][CH:2]1[C:7]([CH3:8])([CH3:9])[O:6][C:5]2[CH:10]=[CH:11][S:12][C:4]=2[CH:3]1[N:13]1[CH2:17][CH2:16][CH2:15][C:14]1=[O:18])(=[O:21])[CH3:20]

Komponenten

4

Edukt 2

HCID 7918Acetic AnhydrideHCID 99034645,6-Dihydro-6-hydroxy-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran

Produkt 1

HCID 149864996-Acetoxy-5,6-dihydro-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 24247Perchloric AcidKatalysator

Versuchsvorschrift

A solution of 5,6-dihydro-6-hydroxy-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran (2.0 g, 7.48 mmol) and perchloric acid (70%, 10 drops) in acetic anhydride (20 mL) were stirred for 1 h at 0°-5° C. The solution was poured into ice water (100 mL). The product was extracted into dichloromethane, washed with water (4x), and evaporated in vacuo. The resultant oil was purified by flash chromatography, using 1% methanol in dichloromethane as the eluant, then crystallized from hexanes to give the product, 2.12 g (92%), as a colorless solid: mp 92°-93° C.; IR(KBr): 1745 and 1684 cm-1 ; MS: 310 (MH+); 1 1H NMR (CDCl3): w 1.37 (s, 3H), 1.38 (s, 3H), 1.98 (m, 2H), 2.10 (s, 3H), 2.37 (m, 2H), 3.24 (m, 1H), 3.40 (m, 1H), 5.15 (d, J=9.1 Hz, 1H), 5.44 (d, J=9.1 Hz, 1H), 6.58 (d, J=5.4 Hz, 1H) and 7.13 (d, J=5.4 Hz, 1H).

Aufarbeitung

  1. extractionThe product was extracted into dichloromethane
  2. washwashed with water (4x)
  3. customevaporated in vacuo
  4. customThe resultant oil was purified by flash chromatography
  5. customcrystallized from hexanes
  6. customto give the product, 2.12 g (92%)

Quellen und Nachweise

ORD-Eintrag
ord-6c8e14fe524a4e59917aa475c19cdadb
Quelldatensatz
uspto-grants-1994_02
Patentnummer
US05284857

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