Hydrochloric Acid → HCID 10656903, compound

Participants

Reaction Steps

A mixture of 0.5 g of N-isopropyl-4-aminopyridine-3-sulfonamide (Preparation 7) and 0.5 g of paraformaldehyde in 15 cm3 of isopropanol to which 50 drops of ethyl acetate saturated with gaseous HCl have been added is brought to reflux for 24 hours. After this lapse of time, the solvent is removed under partial vacuum. The residue is redissolved in 20 cm3 of methanol. The possible insoluble material is removed by filtration. The filtrate, treated with 40 cm3 of water and stored for 2 hours at +4° C., produces a precipitate of the isopropoxymethylenated derivative of Preparation 7. It is collected on a filter, washed with water, dried and recrystallized from a CHCl3 /petroleum ether (40°-60° C.) (1/2) mixture. The dry product is introduced into an open round-bottomed flask and brought to a temperature of 180°-190° C. After 15 to 30 minutes, the molten mass solidifies. It is then cooled and then dissolved in a small volume of chloroform. The addition of 1 volume of petroleum ether (40°-60° C.) causes precipitation of crystals of the title compound. They are collected on a filter, washed with petroleum ether (40°-60° C.) and dried.

Provenance & Evidence