Reaktion #85679

Reaktionsgleichung

HCl

2-chloro-4-methyl-5-(2-(1,1,1-trifluoro-2-methylpropan-2-yl)pyridin-4-yl)thiazole

tributyl(1-ethoxyvinyl)stannane

NaOH

KF

→

1-(4-methyl-5-(2-(1,1,1-trifluoro-2-methylpropan-2-yl)pyridin-4-yl)thiazol-2-yl)ethanone

Ausbeute 49.0%

Lösungsmittel

EtOAc

THF

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated to 100 C for 16 h
2. 2
   SonstigeCopious precipitate formed
3. 3
   FiltrationThe reaction was filtered through Celite
4. 4
   WaschenThe organic layer was rinsed with 60 mL water
5. 5
   Einengenconcentrated
6. 6
   Sonstigeto give grey solid
7. 7
   workup.STIRRINGThe reaction was stirred at r.t. for 2 h
8. 8
   SonstigeTHF was removed in vacuo
9. 9
   WaschenThe organic layers were washed with 50 mL brine
10. 10
    Trocknendried over Na2SO4
11. 11
    FiltrationFiltered
12. 12
    Einengenconcentrated on silica gel

Vorschrift

To a solution of 2-chloro-4-methyl-5-(2-(1,1,1-trifluoro-2-methylpropan-2-yl)pyridin-4-yl)thiazole (3.3 g, 10.3 mmol) and Pd(PPh3)2Cl2 (0.72 g, 1.03 mmol) in 50 mL dioxane under nitrogen, tributyl(1-ethoxyvinyl)stannane (3.82 ml, 11.32 mmol) was added. The mixture was heated to 100 C for 16 h. The reaction was cooled to r.t. and diluted with 25 mL EtOAc. 2M KF (15.4 ml) solution was added and stirred for 1 h. Copious precipitate formed. The reaction was filtered through Celite and chased with EtOAc. The organic layer was rinsed with 60 mL water, and concentrated to give grey solid. Crude solid was dissolved in THF (50 mL) and 1N HCl (20.58 mL) was added. The reaction was stirred at r.t. for 2 h. The mixture was neutralized by addition of 1 N NaOH. THF was removed in vacuo. Extracted aqueous with 2×50 mL EtOAc. The organic layers were washed with 50 mL brine, and dried over Na2SO4. Filtered and concentrated on silica gel. Flash chromatography using 10-50% EtOAc in heptane gave 1.65 g (49%) 1-(4-methyl-5-(2-(1,1,1-trifluoro-2-methylpropan-2-yl)pyridin-4-yl)thiazol-2-yl)ethanone as a yellow oil. MS m/z 329.0 (M+H)+. 1H NMR (400 MHz, CDCl3) δ 8.72 (dd, J=5.2, 0.9 Hz, 1H), 7.60 (dq, J=1.8, 0.9 Hz, 1H), 7.34 (dd, J=5.1, 1.6 Hz, 1H), 2.74 (s, 3H), 2.63 (s, 3H), 1.69 (s, 6H).

Quelle