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2‐(4′‐Hydroxyphenylbenzoyl)benzoic acid is readily available from phenolphthalein by reaction with hydroxylamine. On treatment with hydrazine, 4‐(4‐hydroxyphenyl)phthalazin‐1‐one is formed in high yield. Under conditions conventionally used for the synthesis of poly(aryl ether)s the phthalazinone reacts with 4,4‐difluorobenzophenone or 4,4′‐difluorodiphenyl sulfone to yield high molecular weight linear polymers which are thermooxidatively stable and have Tg's approaching 300°C. The phthalazinone NH groups behave like phenolic OH groups and the resulting polymers contain O‐C and N‐C linkages. Phenyl‐substituted phenolphthaleins have also been synthesized and converted to the corresponding phthalazinone polymers.

MARTINO PAVENTI and JOHN T. EDWARD. Can. J. Chem. 65, 282 (1987). The conversion of aldehydes into a-aminonitriles and thence into imidazolidin-4-thiones has been studied. Hydrolysis of the appropriate imidazolidin-4-thiones gave thioamides of nine naturally occurring a-amino acids. The possible pre-biotic significance of these compounds is discussed.MARTINO PAVENTI et JOHN T. EDWARD. Can. J. Chem. 65,282 (1987). On a CtudiC la transformation des aldChydes en a-amino-nitriles et Cventuellement en imidazolidinethiones-4. L'hydrolyse des imidazolidinethiones-4 appropriCes conduit aux thioamides de neuf acides a-aminCs naturels. On discute de I'implication prC-biotique possible de ces composts.[Traduit par la revue]In 1953, Miller (1) showed that sparking a mixture of methane, ammonia, hydrogen, and water vapour furnished traces of glycine, alanine, and other common a-amino acids. This historic experiment awakened the interest of many organic chemists in possible pre-biotic routes to proteins, nucleic acids, and polysaccharides on the primitive earth.It seems likely that under the conditions of Miller's experiment aldehydes and hydrogen cyanide are formed (2). These can react with ammonia to give a-aminonitriles 1, which are hydrolysed to a-amino acids-(2). However, the polymerization .of a-amino acids to polypeptides and proteins requires an activation process. Various possible modes of activation that might operate under pre-biotic conditions (heat, cyanamide, adsorption on clays, etc.) have been suggested (2, 3) but are not very plausible.This activation step might have been avoided on the primitive earth if a-aminonitriles had been converted into reactive a-amino acid derivatives rather than into unreactive a-amino acid zwitterions. One such derivative might have been the thioamide. The reactivity of these compounds was demonstrated more than 70 years ago by Johnson and Burnham (4), in the course of their attempts to obtain the thioamide 2 (R' = R~ = H) by treatment of the nitrile 1 (R' = R2 = H) amounts of the cyclic product 4 (R' = R2 = H), all presumably arising from further reaction of the sought-for thioamide 2 (R1 = R 2 = H) (Scheme 1). Later attempts by Gatewood and Johnson (5,6) to obtain other a-aminothioamides by this route gave either no product (6), or products from further reaction of initially formed a-aminothioamides (5, 6). However, Cook et al. (7) obtained 2 (R' = Ph, R2 = H) in 12% yield by treating 1 (R' = Ph, R2 = H) with H2S for 24 h in ether containing a little pyridine.This work indicates a possibility of producing thiopolypeptides and thence polypeptides by the general route of Scheme 1.Consequently, we have prepared a-aminothioamides 2 corresponding to several common a-amino acids a s a preliminary t o searching for conditions to convert them into linear thiopolypeptides.We first required a convenient and general preparation of a-aminonitriles 1. These compounds have long been obtained by the Strecker reaction: ience, NH4Cl and NaCN (= NaCl + NH4CN = NaCl + NH3 + HCN) were used instead...

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Attempts to hydrolyse the nitrile group of 2-aminoadamantane-2-carbonitrile by mineral acid or alkali have been unsuccessful. However, treatment of the aminonitrile with benzaldehyde in alkaline solution gives the benzal derivative of the α-aminoamide, readily hydrolysed to the α-aminoamide. Alternatively, benzoylation of the amino group followed by acid hydrolysis gives successively the α-benzamido acid and the α-amino acid. Possible mechanisms for these facilitated hydrolyses are advanced.