Hydrochloric Acid → 4-Chlorophenyl Isocyanate

Participants

Reaction Steps

4-Chlorophenyl urea (8.5 parts) and a solution of sodium nitrite (6.9 parts) in water (10 parts) were added over 6 hours to a mixture of conc. hydrochloric acid (10.3 parts) chloroform (130 parts) and tetra-n-butyl ammonium fluoroborate (10% by weight based on 4-chlorophenyl urea) at -10° to -5° C. The mixture was stirred for a further 15 minutes then the stirrer stopped and layers allowed to separate. No solid was present at this stage. 5 mls of the organic layer was taken for analysis and the remainder kept cold until required.

Provenance & Evidence