Abstract: The preparation of N-(aryl)-1,2,4-triazolopyrimidine-2-sulfonamides by the coupling of substituted 1,2,4-triazolopyrimidine-2-sulfonyl halides with aryl amines of substantially reduced nucleophilic reactivity is facilitated by conducting the reaction in the presence of a pyridine base and a catalytic amount of dimethyl sulfoxide.

Abstract: 2-Alkylthio-4-hydrazino-5-fluoropyrimidines can be prepared from 2,4-dichloro-5-fluoropyrimidine in good yield with high selectivity by treatment with 2 equivalents of alkyl mercaptan in the presence of base followed by treatment with hydrazine.

Abstract: Nitro-substituted 2-(2-hydroxyphenyl)benzoxazoles of the formula ##STR1## wherein one of R.sup.3 and R.sup.4 is --NO.sub.2 and the other is --H, --NO.sub.2 or alkyl of 1 to 20 carbons and R.sup.1 and R.sup.2 independently are --H or alkyl of 1 to 20 carbons, with the proviso that R.sup.1, R.sup.2, R.sup.3 and R.sup.4 contain a total of at least 7 carbons, are acidic, oil soluble compounds having utility for extraction of copper from strongly acidic ore leaches. Excellent selectivity for copper over iron is exhibited by the subject compounds.

Abstract: New chelate exchange resins capable of selective recovery of copper, nickel, and other valuable metals from an acidic aqueous leach liquor are prepared by reacting a crosslinked haloalkyl polymer matrix resin (I) with certain aminopyridines (II) to give a resin (III) ##STR1## with pendent methyleneaminopyridine groups attached to the matrix resin. Particularly useful resins are obtained by reacting chloromethylated styrene-divinylbenzene copolymer beads with an aminomethylpyridine, such as 2-picolylamine, N-methyl-2-picolylamine, N-(2-hydroxyethyl)-2-picolylamine, N-(2-methylaminoethyl)-2-picolylamine, or bis-(2-picolyl)amine. At a typical copper ore leach liquor pH of about 2, the picolylamine resins will absorb 15-30 mg copper/ml resin with a 5-10 fold selectivity for copper over ferric iron.

Abstract: New chelate exchange resins capable of selective recovery of copper, nickel, and other valuable metals from an acidic aqueous leach liquor are prepared by reacting a crosslinked haloalkyl polymer matrix resin (I) with certain aminopyridines (II) to give a resin (III) ##STR1## with pendent methyleneaminopyridine groups attached to the matrix resin. Particularly useful resins are obtained by reacting chloromethylated styrene-divinylbenzene copolymer beads with an aminomethylpyridine, such as 2-picolylamine, N-methyl-2-picolylamine, N-(2-hydroxyethyl)-2-picolylamine, N-(2-methylaminoethyl)-2-picolylamine, or bis-(2-picolyl)amine. At a typical copper ore leach liquor pH of about 2, the picolylamine resins will absorb 15-30 mg copper/ml resin with a 5-10 fold selectivity for copper over ferric iron.