Takeo Higashino

Preparation of heteroarenecarbonitriles by reaction of heteroarene N-oxides with trimethylsilyl cyanide in the presence of DBU

Several heteroarenecarbonitriles were prepared from the corresponding heteroarene N-oxides by treatment with trimethylsilyl cyanide (TMSCN) in the presence of a base in tetrahydrofuran (THF). 1,8-Diazabicyclo [5.4.0]-7-undecene (DBU) was found to be an effective base for the cyanation

Purines. IX, Reaction of 9-phenyl-9H-purine-2-carbonitriles with Grignard reagents

The palladium-catalyzed cross-coupling reaction of 2- and 6-chloro-9-phenyl-9H-purines with potassium cyanide proceeded to give 9-phenyl-9H-purine-2- (3a-c) and -6-carbonitriles (4a-c). The conversion of the cyano group at the 2-position into the corresponding acyl groups was achieved by treatment of 3a,b with Grignard reagents

Pyrazolopyridines. 1. Formylation and Acylation of Pyrazolo[1,5-a]pyridines

In the treatment of pyrazolo(1,5-a]pyridines with dimethylformamide and,phosphorus oxychloride, Vilsmeier-Haack formylation proceeded at the 3-position, giving 3-pyrazolo[1,5-a]pyridinecarboxaldehydes. Reaction of the pyrazolo[1,5-a]pyridine with acyl halide gave 3-acylpyrazolo[1,5-a]pyridines. Conversion of the formyl group into the alkenyl group was achieved easily by Wittig reaction

Ring opening of 4-chloroquinazoline into 2-arylmethyleneaminobenzonitrile by Grignard reaction

The treatment of 4-chloroquinazoline (1) with arylmagnesium bromide (3) in tetrahydrofuran (THF) resulted in the formation of 2-arylme- thyleneaminobenzonitrile (2). Continued reaction of ring opening of (1) and subsequent hydrolysis of the products (2) afforded the corresponding arenecarbaldehydes (4)