Continuous process for diazomethane from an n-methyl-n- nitrosoamine and from methylurea through n-methyl-n-nitrosourea

摘要

Diazomethane is produced in a continuous process with little or no explosion hazard, by dissolving an N-methyl-N-nitroso amine in a mixture of a water-miscible organic solvent that dissolves the N-methyl-N- nitroso amine and a water-immiscible organic solvent that dissolves diazomethane, and combining a stream of this solution with a stream of an aqueous inorganic base, allowing the aqueous and organic phases to settle after a suitable residence time, and phase separating the phases, all on a continuous basis. When using N-methyl-N-nitrosourea as the amine, the diazomethane process is preceded by a continuous nitrosation process involving combining aqueous solutions of methyl urea and a nitrite salt with an organic solution of a mineral or organic acid, the solvent in the organic solution being a mixture of the two organic solvents referred to above, allowing the aqueous and organic phases to settle after a suitable residence time, and phase separating the phases, all on a continuous basis. The resulting organic phase is continuously fed to the diazomethane stages described above.