Reacción #1256705

Ecuación de reacción

4-bromo-3,5-dimethyl-pyridine 1-oxide

2

4-methoxy-2,6-dimethylphenylboronic acid

dicyclohexyl-(2-phenanthren-9-yl-phenyl)-phosphane

K3PO4

→

title compound

Rendimiento 1.8%

4-(4-methoxy-2,6-dimethyl-phenyl)-3,5-dimethyl-pyridin-1-ol

Rendimiento 1.8%

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe Schlenk tube was next evacuated
2. 2
   OtroThen, degassed dry toluene (100 mL)
3. 3
   workup.ADDITIONwas added via syringe under N2
4. 4
   OtroThe Schlenk tube was sealed
5. 5
   TemperaturaThe reaction mixture was subsequently cooled to room temperature
6. 6
   workup.ADDITIONdiluted with methylene chloride (500 mL)
7. 7
   Filtraciónfiltered
8. 8
   Concentraciónconcentrated in vacuo
9. 9
   Otroto stand at room temperature until the colorless crystalline product
10. 10
    Otroseparated from the liquid
11. 11
    FiltraciónThe solid was then collected by filtration
12. 12
    OtroThe filtrate was purified by flash chromatography
13. 13
    Lavadoeluting with 95:5 CHCl3

Procedimiento

A flame-dried sealable Schlenk tube was charged with 4-bromo-3,5-dimethyl-pyridine 1-oxide (1; 10.1 g, 50.0 mmol), 2 (18.0 g, 100 mmol), Pd2(dba)3 (0.915 g, 1.00 mmol), dicyclohexyl-(2-phenanthren-9-yl-phenyl)-phosphane (1.8 g, 4.0 mmol), and K3PO4 (31.9 g, 150 mmol). The Schlenk tube was next evacuated and backfilled with N2. Then, degassed dry toluene (100 mL) was added via syringe under N2. The Schlenk tube was sealed, and the mixture was stirred at 120° C. for 48 h. The reaction mixture was subsequently cooled to room temperature, diluted with methylene chloride (500 mL), filtered, and concentrated in vacuo. The resulting dark brown oil was allowed to stand at room temperature until the colorless crystalline product separated from the liquid. The solid was then collected by filtration and identified as the pure title compound (6.55 g). The filtrate was purified by flash chromatography eluting with 95:5 CHCl3: methanol to afford an additional 0.23 g of the title compound. The combined yield was 6.78 g (53%): mp 194-195° C.; 1H NMR (400 MHz, CD2Cl2): δ 7.990 (s, 2H), 6.705 (s, 2H), 3.798 (s, 3H), 1.892 (s, 6H), 1.842 (s, 6H); 13C NMR (125 MHz, CD2Cl2): δ 159.771, 139.578, 137.663, 137.187, 135.775, 128.289, 113.709, 55.605, 20.198, 17.087; MS (ESI): m/z 258.4 [(M+H)+, 100]; Anal. Calcd. For C16H19NO2: C, 74.68; H, 7.44; N, 5.44. Found: C, 74.54; H, 7.40; N, 5.51.

Fuente