4 5 to 5 5 in a suitable non reactive solvent preferably but not limited to acetonitrile or alcohols such as methanol at a temperature between 40 u00b0 and 80 u00b0 c preferably at 20 u00b0 c to 30 u00b0 c the acid binding agent used may be any weakly basic anhydrous material but is preferably a weak tertiary amine base such as pyridine or an alkali metal carboxylic acid salt such as sodium acetate and is preferably used in amounts of between 0 5 to 1 5 equivalents based on the total amount of acid bound in the compounds of formulae iii and iv hydrazincs of formula iii are either known or can be prepared by various methods known to one skilled in the art for example u s pat no 4 881 967 and references cited therein describe the preparation of hydrazincs by diazotization of appropriately substituted amines known in the art str10 wherein q is as described previously preparation of formula i compounds stage c is as a rule carried out by allowing a compound of formula ii to react optionally with a solvent at a temperature between 0 u00b0 and 150 u00b0 c advantageously in the presence of an acidic catalyst either at atmospheric subatmospheric or superatmospheric pressures scheme iii a wide range of solvents may be used but are preferably non ketonic neutral or only weakly acidic especially preferred are toluene acetone ethyl acetate and isopropyl acetate preferably used in amounts of between.