Parallel solid-phase syntheses of 1,3,4-thiadiazolium-2-aminides.
An efficient and advantageous solid-phase strategy has been developed to synthesize 1,3,4-thiadiazolium-2-aminides. The title compounds were prepared in parallel fashion according to the following compact route: (i) anchoring of aromatic aldehydes to the solid support; (ii) solution preparation of 1,4-disubstituted thiosemicarbazides from hydrazines plus isothiocyanates; (iii) trimethylsilyl chloride-promoted cyclization between the resin-bound aldehydes and 1,4-disubstituted thiosemicarbazides; and (iv) removal of the products from the solid support by acid treatment. The products (17 made in all) were cleaved with high initial purities (90-98%) and obtained in generally good isolated yields (53-94%, with one exception).
Kappel
Joseph C
JC
Department of Chemistry, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455, USA.
Yokum
T Scott
TS
Barany
George
G