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). 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 record

ord-fec93f1ccaf64220ac4b8fe1b234f924

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08134001B2