2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2-Chloro-4,5-dimethylpyrimidine

Temperature

0 °C

To 2-chloro-5-methylpyrimidine (EXAMPLE 144, STEP 1) (0.50 g, 0.00389 mol) in diethyl ether (12 mL) at −30° C. and under nitrogen was added dropwise 1.4M methyllithium (2.90 mL, 0.00405 mol) and the reaction allowed to stir at −30° C. for 30 min and at 0° C. for 30 min. The reaction was quenched with a solution of acetic acid (0.242 mL), water (0.039 mL, and THF (0.8 mL) and then a solution of DDQ (0.92 g, 0.00405 mol) in THF was added. The reaction was stirred 5 min at rt, recooled to 0° C. and 3N sodium hydroxide added. The reaction was allowed to stir at 0° C. for 30 min after which a thick oily precipitate formed. The organic supernatant was decanted and the residue washed with diethyl ether (2×20 mL). The organic layers were dried over sodium sulfate, filtered through a pad of silica and the silica pad washed with diethyl ether. The filtrate was concentrated in vacuo to give the title compound as an oil. M.S. (M+1): 143.

1. customThe reaction was quenched with a solution of acetic acid (0.242 mL), water (0.039 mL, and THF (0.8 mL)
2. stirringThe reaction was stirred 5 min at rt
3. customrecooled to 0° C.
4. stirringto stir at 0° C. for 30 min after which a thick oily precipitate
5. customformed
6. customThe organic supernatant was decanted
7. washthe residue washed with diethyl ether (2×20 mL)
8. dry with materialThe organic layers were dried over sodium sulfate
9. filtrationfiltered through a pad of silica
10. washthe silica pad washed with diethyl ether
11. concentrationThe filtrate was concentrated in vacuo

ORD record

ord-846f25a974ce498e955920d2b08e4a1d

Source dataset

uspto-grants-2007_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07217716B2