Dimethyl Sulfate → 2-methoxy-1-methyl-4,5,6,7-tetrahydro-3H-azepinium methylsulfate

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Reaction Steps

Stir 190 g of N-methylcaprolactam and 189 g of dimethylsulfate for 3 hours at 80° C. Cool the resulting reaction mixture to ambient temperature before shaking it with diethyl ether and then freeing it from solvent residue in vacuo to obtain 346 grams (g) of 2-methoxy-1-methyl-4,5,6,7-tetrahydro-3H-azepinium methylsulfate as a light yellow oil. Add this oil, drop by drop, to a solution of 110 g of dimethylamine in 600 milliliters (ml) of benzene while stirring and boil the thus-prepared admixture under reflux for 90 minutes. Collect the heavy phase and extract it several times with diethyl ether. Concentrate the produced yellowish oil in vacuo to obtain 336 g (93% of theory) of the title compound.

Provenance & Evidence