Approach to green chemistry of DMT-MM: recovery and recycle of coproduct to chloromethane-free DMT-MM

A simple procedure for the isolation of 2-hydroxy-4,6-dimethoxy-1,3,5-triazine (HO-DMT), a coproduct arising from dehydrating condensation using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) has been established. HO-DMT can be recycled by treatment with POCl3 to give 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT), which is further converted to DMT-MM. Alternatively, reaction with triflic anhydride followed by addition of N-methylmorpholine gives DMT-MM triflate.