Add time:08/14/2019         Source:sciencedirect.com

The title compound, a potential intermediate to protected C-nucleoside analogs related to formycin A, was synthesized via a new route wherein 2,3,5-tri-O-benzyl-1-O-p-nitrophenyl)-d-ribofuranose was converted to 2,5-anhydro-3,4,6-tri-O-benzyl-d-allonic acid, and further transformed into 4-(tert-butyloxycarbonyl)-5-ethoxycarbonyl-3-(2,3,5-tri-O-benzyl-β-d-ribofuranosyl)pyrazole. After amidation and dehydration to form the 4-(tert-butyloxycarbonyl)-5-pyrazolecarbonitrile, acidolysis followed by a Curtius-type sequence afforded the 4-amino-5-pyrazolecarbonitrile nucleoside. Treatment of the latter with nitrous acid and copper chloride in a Sandmeyer-type reaction gave a diazonitrile rather than a chloronitrile. Attempts to convert either the aminonitrile or the diazonitrile to 5,7-diamino-3-(2,3,5-tri-O-benzyl-β-d-ribofuranosyl)pyrazolo[4,3-d] pyrimidine (5-aminoformycin A) by condensation with guanidine or N,N-dimethylguanidine were unsuccessful. Condensation of the aminonitrile with carbon disulfide in pyridine provided access to the formycin system in the form of 3-(2,3,5-tri-O-benzyl-β-d-ribofuranosyl)pyrazolo[4,3-d]pyrimidine-5,7-dithione.

We also recommend Trading Suppliers and Manufacturers of 3-Amino-4-pyrazolecarbonitrile (cas 16617-46-2). Pls Click Website Link as below: cas 16617-46-2 suppliers