Naphthyl cyanoketene N , S -acetals in glycoside synthesis: a new preparative route to a new class of N -naphthylcyanoacrylamide thioglycosides and their conversions to naphthyl-pyrazole hybrids.

The novel N -naphthylcyanoacrylamide thioglycosides 4 were readily prepared by the reaction of N -napthylcyanoacetamide 1 with aryl isothiocyanates in the presence of potassium hydroxide, followed by coupling of the produced salts 2 with 2,3,4,6-tetra- O -acetyl-α-d-gluco- and galacto-pyranosyl bromides 3 . The N -naphthyl acrylamide thioglycoside 12 was prepared by the reaction of N -napthylcyanoacetamide 1 with glucose isothiocyante 10 in the presence of potassium hydroxide, followed by alkylation of the produced salt 11 with methyl iodide. The reaction of thioglycoside compounds 4 with hydrazines afforded the corresponding naphthyl-pyrazole hybrids.