Preparation of nitrogen-containing pi-deficient heteroaromatic Grignard reagents: oxidative magnesiation of nitrogen-containing pi-deficient halogenoheteroaromatics using active magnesium.
The oxidative magnesiation of nitrogen-containing pi-deficient halogenoheteroaromatics using active magnesium was accomplished. Both magnesiation followed by addition of a carbonyl compound (Grignard reaction) and magnesiation in the presence of a carbonyl compound (Barbier reaction) were carried out to afford the corresponding product. Especially, the latter method enabled fused halogenodiazines such as 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine or 2-chloroquinoxaline to magnesiate at a mild temperature (-20 to 30 degrees C).
Sugimoto
Osamu
O
Laboratory of Organic Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan. osamu@smail.u-shizuoka-ken.ac.jp
Yamada
Shigeru
S
Tanji
Ken-ichi
K