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The synthesis of bromopyrazines from hydroxypyrazines was successfully effected by the procedure via trimethylsilyloxypyrazines, the sequence of which proceeds under mild conditions and does not require the isolation of intermediate.

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CO 2 emission from the zinc production by recycling of the Electric Arc Furnace dust (EAF dust) was quantitatively evaluated using Life Cycle Assessment (LCA) technique. EAF dust is used as one of the raw materials in pyrolytic zinc for the smelter. So, inventories for this study such as fuel consumption of unit process and inhouse electricity were established based on literatures and the public statistical data. The analysis of Life Cycle Inventory (LCI) has been conducted and as a result, the followings have been observed.(1)̙The amount of CO 2 emission from the pyrolytic zinc production is about 3.4 kg / kg-zinc. 40 % of the whole CO 2 emission is originated by the coke combustion in the smelting furnace. And, 20 % of the whole CO 2 emission is attributable to the separation process of EAF dust. (2)̙If recycling of EAF dust to pyrolytic zinc is accelerated, the amount of CO 2 emission from zinc production is increased under the assumption that the energy consumption in the stabilization process of EAF dust is negligible. This is attributable to the difference of the energy consumption to convert to the roasted ore from the raw materials. As a result, the present zinc recycling system from EAF dust has disadvantage from the viewpoint of the CO 2 emission. Hence, the projected recycling systems of metal recovery in the steel industry are expected to reduce the energy consumption. However, the recycling of the EAF dust must be evaluated from not only the CO 2 emission, but also impact assessment based on the resources exhaustion, the global warming, the land use and so on. Impact assessment methodology must be developed to evaluate the validity of the recycling of EAF dust.

The reduction effects of CO 2 emission from typical steel products by the reduction agent injection into blast furnace were analyzed by Life Cycle Assessment methodology, using the statiscal data.As the results, the reduction effects by pulverized coal injection and waste plastic injection were estimated to be 0.07 kg and 0.16 kg CO 2 at the point of 0.1 kg/kg HM of injection, respectively. As the coke is replaced with pulverized coal on the equivalent in carbon content, the CO 2 emission from the coke manufacturing is reduced. And the reduction effect of CO 2 emission by waste plastic injection is higher than that by pulverized coal injection, because the replacement ratio of coke with waste plastics is higher. The injection ratio of waste plastics would not be raised to the same ratio as the pulverized coal in the viewpoint of the material balance of waste plastics.

Synthesis of acetylpyrazines 3 and propionylpyrazines 5 was achieved by copper-cocatalytic Stille reaction of bromopyrazines 1 with tributyl(1-ethoxyalkenyl)tin and then acidic hydrolysis. The optimal reaction conditions involve the combination of 15 mol% CuI with 5 mol% of PdCl 2 (Ph 3 P) 2 . Similarly, 2-acylpyridines and propionylbenzenes were prepared from the corresponding aryl bromides.The Stille cross-coupling of bromobenzenes with trialkyl(1-ethoxyvinyl)tin followed by acidic hydrolysis has been shown as a convenient method for the synthesis of acetophenones. 2,3 In a preceding paper, we reported this methodology to be also effective in the dehalogenative acylation of electron-deficient nitrogen heteroaromatics, thus high yields of 1,3-dihydro-6-propionylpterin-2,4-diones were synthesized via Pd-catalyzed reaction of the 6-bromopteridines with tributyl(1-ethoxyprop-1-enyl)tin. 1 The key for the successful transformation was the use of CuI under the traditional Stille conditions, in other words the cross-coupling did not proceed at all without the additive. The cocatalytic effect of CuI in the Stille coupling was first reported by Liebeskind and Fengl, 4 and the many subsequent applications have stimulated a considerable development in this chemistry. 5 Much less is known, however, about the couplings of aryl halides with trialkyl(1-ethoxyalkenyl)tin in the presence of CuI. 6 On the other hand, acylpyrazines are of interest as the constituents in foodstuffs or pheromones, which have been often prepared by the Minisci-type radical reaction of pyrazines 7 or lithiation followed by reaction of the resultant lithiopyrazines with N,N-dialkylamides. 8 These methods suffer from some drawbacks, especially the regioselectivity of aromatic substitution. In this respect, acylation via displacement of halogeno substituent is a promising synthetic route to the desired acylpyrazines. We are currently investigating the acylation of bromopyrazines through copper-cocatalytic Stille reaction with 1-ethoxyvinyl or 1-ethoxypropenyl tin compounds (Scheme 1). Additionally, the cross-coupling of halogenopyridines and bromobenzenes was carried out under similar conditions for comparison of reactivity with pyrazine series.We first examined Pd-catalysts in the cross-coupling of 2-bromo-5-phenylpyrazine (1a) 9 with tributyl(1-ethoxyvinyl)tin (2), in which 5 mol% each of Pd catalyst and CuI were employed in refluxing MeCN containing triethylamine (Table 1, entries 1-3) according to our previous procedure. 1 Consequently, PdCl 2 (Ph 3 P) 2 induced the best yield (81%) of 2-acetyl-5-phenylpyrazine (3a). When toluene 2 was used as the solvent instead of MeCN, the yield of 3a decreased to 72%. The effects of Pd-catalyst, CuI and triethylamine can be realized from the experiments lacking each additive (entries 4-9). Without the Pdcatalyst, the coupling proceeded only slightly. The addition of CuI unexpectedly led to an appreciable increase in the yield of acetylpyrazine 3a. Our previous cross-coupling of bromopteridines necessitated cat...

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