Multi-stage nitration of cyclohexane

Claim 1

A MULTI-STAGE VAPOR PHASE PROCESS OF MONONITRATING AN ALKANE HAVING FROM 2 TO 7 CARBON ATOMS, COMPRISING: (A) MIXING VAPORS OF THE ALKANE AND VAPORS OF A NITRATING AGENT SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID AND NITROGEN DIOXIDE IN THE ABSENCE OF LIQUID PHASE REACTANTS, IN THE PROPORTIONS OF AT LEAST 4 MOLS OF THE ALKANE PER MOL OF NITRIC ACID WHEN USING NITRIC ACID AS THE NITRATING AGENT, AND AT LEAST 1 MOL OF THE ALKANE PER MOL OF NITROGEN DIOXIDE CALCULATED AS NO2, WHEN USING NITROGEN DIOXIDE AS THE NITRATING AGENT AT A TEMPERATURE BELOW THAT AT WHICH SUBSTANTIAL NITRATION OCCURS; (B) PASSING THE RESULTANT VAPOR MIXTURE INTO THE FIRST OF A PLURALITY OF REACTION ZONES, IN EACH OF WHICH THE TEMPERATURE IS MAINTAINED WITHIN THE RANGE OF FROM 250* TO 375*C. AND THE RESIDENCE TIME FOR THE REACTANTS AND REACTION PRODUCTS IS AT LEAST 20 SECONDS; AND (C) ADMIXING THE REACTION PRODUCTS FROM EACH ZONE WITH ADDITIONAL VAPORS OF THE NITRATING AGENT PRIOR TO PASSAGE OF THE RESULTING MIXTURE TO A SUCCEEDING ZONE, THE OVERALL MOLAR RATIO OF THE ALKANE TO THE NITRATING AGENT SUPPLIED TO THE PROCESS BEING LOWER THAN 4 TO 1 WHEN USING NITRIC ACID AS THE NITRATING AGENT, AND 1 TO 1 WHEN USING NITROGEN DIOXIDE AS THE NITRATING AGENT.