Reaction #742299

Reaction equation

citric acid

Sodium hydride

(S)-3-(3-(tert-butyldimethylsilyl-oxy)azetidin-1-yl)-2-hydroxy-N-(5-methylpyrazin-2-yl)propanamide

4-chloro-1-(2,6-dichloro-phenyl)-1H-pyrazolo[3,4-d]pyrimidine

→

product

Yield 57.6%

(S)-3-(3-(tert-butyldimethylsilyloxy)azetidin-1-yl)-2-(1-(2,6-dichlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-N-(5-methylpyrazin-2-yl)propanamide

Yield 57.6%

Solvents

tetrahydrofuran

water

ethyl acetate

Conditions

Workup

1. 1
   Temperatureto warm to room temperature
2. 2
   workup.WAITstiffed for 2 hours
3. 3
   OtherThe organic layer was separated
4. 4
   Extractionthe aqueous layer re-extracted with ethyl acetate (50 mL)
5. 5
   WashThe combined organics were washed with saturated brine (75 mL)
6. 6
   Dryingdried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Otherevaporated
9. 9
   OtherThe crude product was purified by flash silica chromatography
10. 10
    Washeluting with 40 to 80% ethyl acetate in isohexane

Procedure

Sodium hydride (87 mg, 2.18 mmol) was added to (S)-3-(3-(tert-butyldimethylsilyl-oxy)azetidin-1-yl)-2-hydroxy-N-(5-methylpyrazin-2-yl)propanamide (Intermediate BB2) (400 mg, 1.09 mmol) in anhydrous tetrahydrofuran (15 mL) at 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 10 minutes and then 4-chloro-1-(2,6-dichloro-phenyl)-1H-pyrazolo[3,4-d]pyrimidine (Intermediate BA3) (360 mg, 1.20 mmol) was added. The reaction mixture was allowed to warm to room temperature and stiffed for 2 hours. The reaction mixture was neutralised with 1M citric acid and then diluted with water (30 mL) and ethyl acetate (50 mL). The organic layer was separated and the aqueous layer re-extracted with ethyl acetate (50 mL). The combined organics were washed with saturated brine (75 mL), dried (MgSO4), filtered and evaporated. The crude product was purified by flash silica chromatography, eluting with 40 to 80% ethyl acetate in isohexane, to afford the product (395 mg, 57.5%). 1H NMR (400 MHz, CDCl3) δ 0.04 (6H, s), 0.88 (9H, s), 2.54 (3H, s), 3.09-3.13 (2H, m), 3.16-3.21 (1H, m), 3.29-3.34 (1H, m), 3.87-3.92 (2H, m), 4.51 (1H, qn), 5.92-5.95 (1H, m), 7.43-7.47 (1H, m), 7.52-7.55 (2H, m), 8.14 (1H, d), 8.41 (1H, s), 8.59 (1H, s), 9.42 (1H, d), 9.96 (1H, s); m/z (ES+) (M+H)+=631; HPLC tR=2.94 min.

Source