182494-75-3

Upstream product

• 23846-36-8 1-(O⁵-acetyl-O²,O³-isopropylidene-β-D-ribofuranosyl)-5-amino-1H-imidazole-4-carboxylic acid amide 
• 3676-69-5 5-Amino-1-((3aR,4R,6R,6aR)-6-hydroxymethyl-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl)-1H-imidazole-4-carboxylic acid amide 
• 182494-72-0 Acetic acid (3aR,4R,6R,6aR)-6-(4-cyano-5-trimethylsilanylethynyl-imidazol-1-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl ester 
• 182494-70-8 5-iodo-1-(5-O-acetyl-2,3-O-isopropylidene-β-D-ribofuranosyl)imidazole-4-carboxamide 
• 182494-71-9 5-iodo-1-(5-O-acetyl-2,3-O-isopropylidene-β-D-ribofuranosyl)imidazole-4-carbonitrile 
• 182494-73-1 5-ethynyl-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)imidazole-4-carbonitrile 
• 182494-74-2 1-[(3aR,4R,6R,6aR)-6-(1,3-Diphenyl-imidazolidin-2-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl]-5-ethynyl-1H-imidazole-4-carbonitrile 

Downstream Products

• 118908-07-9 5-ethynyl-1-(β-D-ribofuranosyl)imidazole-4-carboxamide 

Relevant academic research and scientific papers

Syntheses of [2-2H]-5-ethynyl-1-(β-D-ribofuranosyl) imidazole-4-carboxamide and 5-ethynyl-1-([5-3H]-β-D-ribofuranosyl)imidazole-4- carboxamide (EICAR)

Metallation of 5-ethynyl-1-(2,3,5-tri-O-tert-butyldimethylsilyl-β-D-ribofura nosyl)imidazole -carboxamide (1) using n-BuLi, deuteration with deuterium oxide and removal of the tert-butyldimethylsilyl protecting groups using tetrabutylammonium fluroide yielded [2-2H]-5-ethynyl- 1-(β-D-ribofuranosyl)imidazole-4-carboxamide (5a, 75 atom % deuterium). Regiospecific deprotection of the masked aldehyde N,N'-diphenylethylenediamino synthon 14 using DIAION PK2I2 ion-exchange resin (H+ form) yielded the aldehyde derivative (15). Reduction of the aldehyde moiety of 15 using excess [3H]NaBH4 gave the carbinol product 17. Removal of the ribofuranosyl 2,3-isopropylidene protecting group from 17 using 90% trifluoroacetic acid afforded 5-ethynyl-1-([5-3H]-β-D-ribofuranosyl)imidazole-4-carboxamide (18. 19% chemical yield, > 99% radiochemical purity, specific activity 1.56 Ci/mmol).