反应详情

Next, 4.7 g of 4-tert-butyl-6-hydroxypyrimidine obtained in Step 1 and 14 mL of phosphoryl chloride were put into a 50-mL three-neck flask, and the mixture was heated and refluxed for 1.5 hours. After the reflux, phosphoryl chloride was distilled off under reduced pressure. The obtained residue was dissolved in dichloromethane, and washed with water and a saturated aqueous solution of sodium hydrogen carbonate. Anhydrous magnesium sulfate was added to the obtained organic layer for drying. This mixture was subjected to gravity filtration, and the filtrate was concentrated. The obtained residue was purified by silica gel column chromatography using hexane and ethyl acetate as a developing solvent in a ratio of 10:1 to give 4-tert-butyl-6-chloropyrimidine (white powder, yield of 78%). Synthesis Scheme (a-2) of Step 2 is shown below.

1. temperaturethe mixture was heated
2. temperaturerefluxed for 1.5 hours
3. distillationAfter the reflux, phosphoryl chloride was distilled off under reduced pressure
4. dissolutionThe obtained residue was dissolved in dichloromethane
5. washwashed with water
6. additionAnhydrous magnesium sulfate was added to the obtained organic layer
7. customfor drying
8. filtrationThis mixture was subjected to gravity filtration
9. concentrationthe filtrate was concentrated
10. customThe obtained residue was purified by silica gel column chromatography