Hydrochloric Acid → 2,4-Diamino-6-methyl-5-[3-(2,5-dichlorophenyl)-2-butenyl]pyrimidine

Participants

Reaction Conditions

Reaction Steps

Zinc is activated by treating 2.5 grams (excess) of it with aqueous 10% hydrochloric acid for two minutes. The activated zinc is collected by filtration, washed with water then acetone, and dried in a vacuum oven for one hour. A solution of 1.5 grams (0.004 mole) of 5-amino-7-methyl-8-[3-(2,5-dichlorophenyl)-2-butenyl]tetrazolo[1,5-c]pyrimidine in 35 mL of acetic acid is stirred, and the activated zinc is added portionwise during a 20 minute period. Upon completion of addition, the reaction mixture is warmed to about 80° C. where it is stirred for about 18 hours. After this time, the reaction mixture is stirred with 50 mL of water. The mixture is then extracted with three 30 mL portions of methylene chloride. The combined extracts are washed with two 10 mL portions of an aqueous solution saturated with sodium bicarbonate. The organic layer is dried with magnesium sulfate and filtered. The filtrate is concentrated under reduced pressure to a residue. The residue is subjected to column chromatography on silica gel, using 15% methanol in methylene chloride as the eluant. The product-containing fractions are combined and concentrated under reduced pressure, yielding 0.4 gram of 2,4-diamino-6-methyl-5-[3-(2,5-dichlorophenyl)-2-butenyl]pyrimidine; mp 172°-174° C. The NMR spectrum is consistent with the proposed structure.

Provenance & Evidence