Ethyl Acetate → Ethyl 6-bromo-8-phenylimidazo[1,2-a]pyridine-2-carboxylate

HRID 1958474Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1958474
Br.[Br:2][C:3]1[CH:4]=[C:5](Br)[C:6]2[N:7]([CH:9]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[N:11]=2)[CH:8]=1.[C:18]1(B(O)O)[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.[O-]P([O-])([O-])=O.[K+].[K+].[K+].C(OCC)(=O)C>C1(C)C=CC=CC=1.C(O)C.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[Br:2][C:3]1[CH:4]=[C:5]([C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C:6]2[N:7]([CH:9]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[N:11]=2)[CH:8]=1

Komponenten

8

Edukt 4

HCID 8857Ethyl AcetateHCID 62657Potassium Phosphate, TribasicHCID 66827Phenylboronic AcidHCID 67007442Ethyl 6,8-dibromoimidazo[1,2-a]pyridine-2-carboxylate hydrobromide

Produkt 1

HCID 58208011Ethyl 6-bromo-8-phenylimidazo[1,2-a]pyridine-2-carboxylateAusbeute 58 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 178418397HCID 178418397, VerbindungKatalysatorHCID 702EthanolLösungsmittelHCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
80 °C

Versuchsvorschrift

A solution of ethyl 6,8-dibromoimidazo[1,2-a]pyridine-2-carboxylate hydrobromide (0.5 g, 1.2 mmol) and phenylboronic acid (0.15 g, 1.2 mmol) in toluene (10 mL) and ethanol (2 mL) was bubbled nitrogen for 20 mins. The mixture was then treated with Pd(PPh3)4 (30 mg, 0.026 mmol) and K3PO4 (2 M, 1 mL, 2 mmol) and heated at 80° C. overnight. The reaction was cooled, poured into ethyl acetate (200 mL), washed with brine, separated, and concentrated. The residue was purified by column chromatography on silica gel using ethyl acetate in hexanes (10%) as eluent. The product containing fractions were concentrated to give 0.23 g (58% yield) of ethyl 6-bromo-8-phenylimidazo[1,2-a]pyridine-2-carboxylate as a white solid. LCMS (Conditions C): 3.41 min (RT); (M+H)+=347.24 (100%), 345.24 (100%). 1H NMR, 400 MHz, CDCl3: δ 8.27 (d, J=1.6 Hz, 1 H), 8.19 (s, 1 H), 8.02 (m, 2H), 7.52-7.41 (m, 4 H), 4.45 (q, J=7.1 Hz, 2 H), 1.42 (t, J=7.0 Hz, 3 H).

Aufarbeitung

  1. temperatureThe reaction was cooled
  2. washwashed with brine
  3. customseparated
  4. concentrationconcentrated
  5. customThe residue was purified by column chromatography on silica gel
  6. additionThe product containing fractions
  7. concentrationwere concentrated

Quellen und Nachweise

ORD-Eintrag
ord-81e5a43598aa46bb8284a4c1f326a778
Quelldatensatz
uspto-grants-2013_04
Patentnummer
US08410128B2

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