Trifluoroacetic acid → 8-Chloromethyl-10H-pyrazino[2,3-b][1,4]benzothiazine

Participants

Reaction Conditions

Reaction Steps

Into 250 ml of a solution of 26.9 g of 8-chloromethyl-10-methoxymethyl-10H-pyrazino[2,3-b][1,4]benzothiazine in methylene chloride was dropped 50 ml of trifluoroacetic acid at 0° C. After reacting at room temperature for 12 hours, the reaction mixture was cooled to 0° C. and neutralized by adding an aqueous solution of sodium hydrogencarbonate. The crystals thus precipitated were taken up by filtration and washed successively with water and diethyl ether to thereby give 19.1 g of the title compound as yellow crystals.

Provenance & Evidence