Potassium Hydroxide → Diazoethane

Participants

Reaction Conditions

Reaction Steps

A solution of approximately 30 mmol diazoethane in 40 ml of ether was prepared by slow addition of 7 g (44 mmol) of 1-ethyl-3-nitro-1-nitrosoguanidine to a mixture of 8 g of potassium hydroxide, 9 ml water and 60 ml of ether followed by distillation. This was slowly added to a solution of 3.2 g (12 mmol) of 5-amino-1-β-D-ribofuranosylimidazole-4-carboxamide (AICA riboside) in 35 ml dimethylformamide containing 50 mg of tin(II) chloride dihydrate. During the addition approximately 20 ml of methanol was added to maintain solubility. The reaction was filtered to remove a trace precipitate and evaporated to a yellow syrup. Thin layer chromatography on silica gel using methylene chloride/methanol (3:1) showed a major product spot moving faster than AICA riboside. The syrup was chromatographed on silica gel using methylene chloride/methanol (8:1) collecting the major product as determined by TLC. The appropriate fractions were evaporated to a white foam. This was dissolved in 7 ml of methanol. Upon cooling to 4° C. the mixture crystallized to yield 160 mg of 5-amino-1-(2-O-ethyl-β-D-ribofuranosyl) imidazole-4-carboxamide (Compound No. 34 (1-250)) confirmed by NMR decoupling and exchange experiments.

Provenance & Evidence