Oximinoaceto-ortho-toluidide prepn - from orthotoluidine hydrochloride, chloral hydrate and hydroxylammonium sulphate in presence of sodium sulphate and ethanol

摘要

Title cpd. useful as precursor for 7-Meisatin which is an intermediate in prepn. of indigo dyes and pharmaceuticals, e.g. (i) virucidal and virus-inhibiting isatin thiosemicarbazones, (ii) anti-malarial quinolines, (iii) isophthalic acid-based x-ray contrast agents, (iv) local anaesthetics, is prepd. by reacting o-toluidine. HCl (II) with choral hydrate (III) and H2NOH. H2SO4 (IV) in presence of anhydrous Na2SO4 and EtOH, using water as solvent, at 20-120 (70-100) degrees C. Pref. 1 mole (II), 1-1.3 moles (III), 2-4 moles (IV), 1.5-3 moles EtOH and 0.2-0.8 moles Na2SO4 are used.