Hydrochloric Acid → HCID 11727549, compound

Participants

Reaction Steps

5.33 g (20 mmoles) of 8-cyclopropyl-3-n-propyl-2,6-dithioxanthine and 21.3 ml (200 mmoles) of 95% 4-picolylamine were heated under argon to 150°-5° C. After 14 hours the cooled solution was poured into 100 ml of water, acidified with 19 ml of 10N HCl to pH 6, where an orange colored gum was formed. With sodium bicarbonate the mixture was neutralized to pH 7. With time the gum crystallized and the solid is collected and washed. The residue was suspended in acetone and the crystals collected: 3.92 (57.6%) of crude product. The filtrate was evaporated to dryness, dissolved in 40 ml of 0.5N NaOH, extracted 4 times with methylene chloride, and acidified again with 5N HCl to pH 6. Again the gum crystallized over 48 hours and the mixture was neutralized to pH 7with bicarbonate and the solid collected: 1.75 g (25.7%) of crude product. Both parts were dissolved in 30 ml of methylene chloride and filtered through 30 g of silicagel in a column 150 mg (2.8%) of starting material was recovered first, then 5.04 g (74.0%) of product was recovered with 5% of methanol, which was dissolved in 32 ml of 1N HCl, treated with 250 mg of charcoal, filtered, and neutralized with 7.5 ml of 2N NaOH and sodium bicarbonate solution to pH 7-8. The water phase was decanted from the gum and the latter washed with water and crystallized from acetone: 4.08 g (59.9%) of thioisoguanine with mp 204°-210° C. with decomposition.

Provenance & Evidence