471250 ml. of saturated ethanolic ammonia was heated in an autoclave a t 135' for 12 hr. The resulting solution was evaporated to dryness and the residue recrystallized from butanol. A final recrystallization from aqueous ethanol afforded an analytically pure product.The structural assignment (see Discussion part) in this group of compounds was further substantiated by paper chromatographic measurements (one spot in each case). Rr values for 2,4-diamino-6-( p-bromoanilino)-5-pyrimidinecarbonitrile: 0.71 (isopropyl alcohol-water, 7 : 3), and 0.80 (butanol saturated with acetic acid); for 2,4-diamino-6-(p-iodoanilino)-5-pyrimidinecarbonitrile: 0.73 and 0.81, respectively.2,4-Diamino-6-( substituted-anilino) -5-pyrimidinecarboxamide (Table I). General Procedure.-With good stirring, 2,4-diamino-6-(substituted-anilino)-5-pyrimidinecarbonitrile (0.05 mole) was added slowly to 50 ml. of concentrated sulfuric acid a t 30-35". The solution was stirred a t this temperature for 12 hr. and then added, with stirring, to 500 g. of flaked ice. The precipitated product was separated by filtration and washed well with icewater. The crude product was dissolved in hot, dilute sulfuric acid, treated with charcoal, and filtered. The filtrate was adjusted to pH 8 with aqueous ammonia and the product filtered while hot, washed with water, and dried at 100'. Repeated reprecipitation afforded product of analytical purity. 4,6-Dichloro-2-methylaminopyrimidine.-In a flask equipped with two modified Friedrichs condensers designed to retain low boiling liquids was added 23 g. (0.23 mole) of triethylamine and 7 g. (0.23 mole) of methylamine diluted with 200 ml. of ethyl acetate. To this solution was added 30 g. (0.154 mole) of 4,6dichloro-2-( methyl~ulfony1)pyrimidine~~ dissolved in 200 ml. of ethyl acetate.The temperature was kept below 35" during the entire reaction. After 2 hr. of stirring the reaction mixture was evaporated and the pale yellow residue recrystallized from ethanol to give 13 g. (77%) of white crystals, m.p. 162-163". The product was found to be identical with that reported by Winkelmann'4* and B 0 0 n . l~~ 4-Amino-6-chloro-2-methylaminopyrimidine.-A mixture of 4,6-dichloro-2-methylaminopyrimidine ( 10.8 g.) and ethanolic ammonia wm heated a t 80' for 8 hr. in a sealed vessel. Evaporation of the reaction mixture and purification of the product from methanol afforded 7 g. (657,) of white crystals, m.p. 193-194". Anal. Calcd. for CsH7ClN4.H20: N, 31.8. Found: N, 31.9. General Preparations of 4-(Substituted-anilino)-5-nitrosopyrimidines (V).A.-A mixture of the appropriate 4chloropyrimidine, an equivalent amount (plus a 10% excess) of the substituted aniline, and several milliliters of concentrated hydrochloric acid was heated in an oil bath. A clear, dark colored melt was observed around 150" followed by an exothermic reaction that caused the temperature to rise to ca. 200". The reaction mixture was held at this temperature for several minutes. It was then cooled, dissolved in boiling ethanol, treated with charcoal, and filt...

Communications to the Editor Vol. 86 furanosyl)purine, m.p. 155-156°, which shows [a]25D + 61.1°( H20), 263.5 µ (e 10,000), infrared bands 9.22 and 12.25 µ (lit.13 m.p. 150-152°, [a]25D +60.0°( H20), X™°2 64 mµ (e 8869)). The concentrated filtrate gave 0.6 g. of 6-chloro-9-(2'-deoxy-/3-D-ribofuranosyl)purine which was recrystallized from a small volume of ethyl acetate to yield 0.45 g. of colorless needles,12 m.p. 144-145°, [a+5n -10.8°( methanol), infrared bands at 8.77 and 10.75 µ, "») 264 µ (e 10,000) (lit.13 m.p. 142-145°, [aj26D -11.0°( methanol), XJJ"" 264 µ (e 8930)). These a-and /3-anomers were

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The direct acid-catalyzed fusion of 6-chloropurine (I) or 2,6-dichloropurine (II) with 3,4-di-O-acetyl-D-arabinal provided a 40-50 % crude yield of crystalline acetylated nucleoside derivatives. The major products were shown to be the corresponding 6-chloroor 2,6-dichloro-9-(3 ',4 '-di-O-acetyl--and ß-2 '-deoxy-o-ribopyranosyl)purine which were separated into pure anomers by preparative layer chromatography and fractional crystallization. The structures of the products were verified by an independent synthesis from the acid-catalyzed fusion of 1,3,4-tri-0-acetyl-2-deoxy-/3-o-ribopyranose and the appropriate purine, which yielded a similar anomeric mixture of the corresponding 9-(3 ',4 '-di-O-acetyl-2 '-deoxyribopyranosyljpurine in about 30% yield, presumably via a common intermediate carbonium ion at Q. The conformation and anomeric configuration has been assigned with the assistance of proton magnetic resonance studies utilizing the double-resonance or proton-proton spin decoupling technique. The ready availability of these 2 '-deoxynucleosides from D-arabinal provides extremely useful synthetic intermediate nucleosides for the preparation of many interesting 9-(2'-deoxy-D-ribopyranosyl)purines of known anomeric assignment. A number of these derivatives obtained by functional group replacement on the purine moiety are reported.The possibility of employing a glycal derivative directly in nucleoside synthesis was first suggested by Robins, et al.f in a model study utilizing various purines and 2,3-dihydropyran and 2,3-dihydrofuran.6•6The fusion procedure of nucleoside synthesis7-10 has proved very successful in recent years in our own laboratory and suggested the possibility of employing an appropriately acetylated glycal directly in an attempt to prepare 2 '-deoxyribopyranosylpurines by a fusion procedure. The use of a 1,2-unsaturated sugar derivative directly has several distinct advantages. For instance, previous procedures have utilized glycals as starting material for subsequent conversion to the requisite 2-deoxy-o-pyranosyl halides which have then been employed in the condensation with the mercury salt of a purine11•12 *or pyrimidine base.1314

Gas-phase polymerization of propylene to high isotactic homopolymers, random copolymers, and impact copolymers has been commercial in the U.S. since 1977. The process incorporates technological improvements including high activity, high stereospecific catalyst, and continuous in-process catalyst deactivation. It produces homopolymers with 97+% heptane insolubles, melt flow rates from fractional to 50+, and a wide range of copolymers.Rapid technological progress was made in developing these improvements through an integrated 1000-ton/year pilot plant in the U.S. to complement similar facilities in Germany. A process description and schematic flow plan for the process, typical product properties, and comparative economics are discussed.