Process to prepare aryltriazolinones and novel intermediates thereto

A process is described for preparing 1-aryltriazolinones of formula I useful in the production of commercial herbicides: by (i) carbonylating an amidrazone of formula (A) with one or more carbonylating agent, or by (ii) condensing a hydrazonoyl derivative of formula (A) with one or more ring-forming agent, wherein formula (A) is where W, X, Y, Z, and R 1 are fully described herein. Preferred are those where W is halogen or —NHR where R is hydrogen or haloalkyl; X and Y are independently selected from hydrogen, chloro, or fluoro; Z is hydrogen, bromo, iodo, nitro, amino, or methylsulfonylamino; and R 1 is methyl. Certain compounds of formula (A) are novel compositions of matter. The process as described herein has utility in providing compounds of formula I in unexpectedly high yield and purity.