Sulfuric Acid → HCID 59484956, compound

Participants

Reaction Conditions

Reaction Steps

5.10 g of N′-[2-(3-acetylphenyl)pyrimidin-5-yl]-N,N-dimethylformamidine (19 mmol) are suspended in 65 ml of water in a 250 ml one-necked flask provided with magnetic stirrer and condenser, 8.44 ml of 95-97% sulfuric acid (152 mmol) are added, and the mixture is stirred at a bath temperature of 130° C. for 2 h. The mixture is diluted with ice-water, during which a dark-brown resin deposits. The aqueous solution is decanted off and extracted with dichloromethane. The combined dichloromethane phases are dried, filtered and evaporated to dryness, and the residue is triturated with ether, filtered off with suction and dried (═K1). The deposited dark-brown resin is extracted by stirring with tetrahydrofuran, filtered off with suction, the crystals are discarded, and the mother liquor is evaporated to dryness (═R1). The aqueous phase from the dichloromethane extraction is evaporated to dryness, the residue is extracted by stirring 2× with tetrahydrofuran, and the combined decanted-off solutions are diluted with di-chloromethane, dried, filtered and evaporated to dryness (═R2). R1 and R2 are combined, adsorbed on silica gel and purified by chromatography (silica gel/dichloromethane+0-5% of methanol). The chromatography residue is triturated with ether, filtered off with suction, washed with ether and dried (═K2).

Provenance & Evidence