Acetyl chloride → 3-Trimethylsilyoxy-2-aza-1,3-butadiene

To 1,1,1,3,3,3-hexamethyldisilazane (4.36 mL, 21 mmol) (Aldrich) under nitrogen at room temperature was added n-butyllithium (2.5 M, 8.4 mL, 21 mmol) (Aldrich). The reaction mixture was stirred at room temperature for 10 minutes. Then dry tetrahydrofuran (60 mL) was added, followed by the addition of 2-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-5-iodo-benzaldehyde (8.53 g, 21 mmol) prepared in Example 190c. After the mixture was stirred at room temperature for 0.5 h, trimethylsilyl chloride (2.66 mL, 21 mmol) (Aldrich) was added dropwise. Then the temperature of the mixture was lowered to 0° C. on a cooling ice bath. To this mixture was added triethylamine (3.8 mL, 27.2 mmol) in one portion, followed by the dropwise addition of a solution of acetyl chloride (1.94 mL, 27.2 mmol) in diethyl ether (100 mL). The cooling bath was removed, and the mixture was stirred at room temperature for 1 h. The mixture was quickly filtered on celite under nitrogen, and filtrate was concentrated under reduced pressure to give crude 1-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-5-iodo-phenyl]-3-trimethylsilyoxy-2-aza-1,3-butadiene as a yellow oil and used for the next step without further purification.

1. stirringAfter the mixture was stirred at room temperature for 0.5 h
2. customThen the temperature of the mixture was lowered to 0° C. on a cooling ice bath
3. customThe cooling bath was removed
4. stirringthe mixture was stirred at room temperature for 1 h
5. filtrationThe mixture was quickly filtered on celite under nitrogen
6. concentrationfiltrate was concentrated under reduced pressure

ORD-Eintrag

ord-96dddcefd6194dca9282dc9c89d2c977

Quelldatensatz

uspto-grants-2009_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07495007B2