Hydrochloric Acid → 5-Methylisocytosine

Participants

Reaction Conditions

Reaction Steps

Freshly prepared sodium methoxide (10.8 g, 200 mmol) was suspended in a solution of ethyl propionate (15.3 g, 150 mmol) in DMF (20 mL) at room temperature. Methyl formate (6.0 g, 100 mmol) was added over a period of 1 hour. After stirring for 30 minutes, a solution of guanidine hydrochloride (9.6 g g, 100 mmol) in MeOH (35 mL) was added rapidly and the reaction mixture was refluxed for 12 hours. After cooling to 30° C. and adjusting the pH to 6.0 with concentrated hydrochloric acid, the slurry was kept at 5° C. for 30 minutes. The solid was collected, washed with methanol, crystallized from water and dried in vacuo to give 5-methylisocytosine (7.3 g, 58.4% yield). 1H NMR (300 MHz, DMSO): δ10.83 (br s, 2H), 7.38 (s, 1H), 6.26 (br s, 2H), 1.72 (s, 3H).

Provenance & Evidence