Iodination of Anisole

As a rule direct iodinations do not proceed readily, often explained as due to the unfavorable equilibrium attained with the reverse reaction of hydrogen iodide upon the iodo-compound. Iodine is more commonly introduced into an aromatic nucleus through the Sandmeyer reaction by the addition of potassium iodide to a diazotized primary aromatic amine. Thus p-iodoanisole has been prepared from p-anisidine.1 A procedure of direct iodination for the preparation of iodoaromatic compounds would appear to offer important advantages. In 1901, Brenans2 reported such a process in the preparation of p-iodoanisole through the interaction of an absolute ethyl alcohol solution of anisole with mercuric oxide and iodine. Later in 1912, Kauffmann3 used the same procedure for the iodination of resorcinol dimethyl ether to produce l-iodo-2, 4-dimethoxybenzene, although he made no reference to the earlier work of Brenans. Blicke and Smith4 in 1928 modified the Brenans procedure for preparation of p-iodoanisole for which they claimed more desirable results. As a result of our experience, we have adopted a procedure more nearly like that of Brenans, giving a better yield and product than would appear from his report, and less involved procedure than that of Blicke and Smith. One mol quantity of anisole is dissolved in about four weight quantities of absolute ethanol, three fourths mol quantity of commercial mercuric oxide is added and slightly more than one mol quantity of iodine introduced in five portions with mechanical shaking between portions until the color of iodine nearly vanished. Finally the whole mixture is shaken for about eight hours on a mechanical shaker. The undissolved mercury compounds are filtered, washed with ethanol, the ethanol removed by distillation, the residual oil dissolved in ether and filtered again if necessary, the ether solution washed with a potassium iodide solution, the ether evaporated, the residual oil steam distilled, and the organic part of distillate crystallized from about 85 per cent ethanol. A yield of 85 per cent, melting at 50.5-51.5 (corrected), was obtained. Some speculation with reference to the role of HgO as a catalyst for this iodination is given. 1 Reverdin, Ber. 29, 1000 (1896). 2 Brenans, Bull. Soc. Chim. [3] 25, 819 (1901). 3 Kauffmann, Ber. 45, 2334-35 (1912). 4 Blicke and Smith, J. Am. Chem. Soc. 50, 1229·30 (1928)

Conservation, Protected Areas and the Global Economic-System - How Debt, Trade, Exchange-Rates, Inflation and Macroeconomic Policy Affect Biological Diversity

The main characteristics of the dominant economic system, including the increasing use of markets and money are described. The global system has expanded trade, including international trade, and production tremendously. While this system has the potential to favour nature conservation, in practice the opposite has occurred. Difficulties raised for conservation of biodiversity by short-term economic crises such as deficits in a country's international payments, the adoption of policies for structural economic adjustment, international capital flows, international loans and foreign aid as well as debt-for-nature swaps are discussed. As explained, it is politically difficult in market economies to support nature conservation at the expense of economic growth and as more economies develop and become market economies this problem spreads. Given global interdependence of nations, an important issue is the distribution of net benefits from biodiversity conservation between developed and less developed countries. Possible distributions of benefits and related issues are discussed. In conclusion, the importance of political lobbying by nature conservation groups in developed market economies is emphasised as a means of ensuring correction of market failures. Unfortunately, no economic system is likely to prove satisfactory in itself in conserving biodiversity so political action by conservationists is always required

Time and frequency structure of causal correlation networks in the China bond market

There are more than eight hundred interest rates published in China bond market every day. Which are the benchmark interest rates that have broad influences on most interest rates is a major concern for economists. In this paper, multi-variable Granger causality test is developed and applied to construct a directed network of interest rates, whose important nodes, regarded as key interest rates, are evaluated with inverse Page Rank scores. The results indicate that some short-term interest rates have larger influences on the most key interest rates, while repo rates are the benchmark of short-term rates. It is also found that central bank bills'rates are in the core position of mid-term interest rates'network, and treasury bond rates are leading the long-term bonds rates. The evolution of benchmark interest rates is also studied from 2008 to 2014, and it's found that SHIBOR has generally become the benchmark interest rate in China. In the frequency domain we detect the properties of information flows between interest rates and the result confirms the existence of market segmentation in China bond market.Comment: 9 pages, 7 figure

Oiling accelerates loss of salt marshes, southeastern Louisiana

The 2010 BP Deepwater Horizon (DWH) oil spill damaged thousands of km2 of intertidal marsh along shorelines that had been experiencing elevated rates of erosion for decades. Yet, the contribution of marsh oiling to landscape-scale degradation and subsequent land loss has been difficult to quantify. Here, we applied advanced remote sensing techniques to map changes in marsh land cover and open water before and after oiling. We segmented the marsh shorelines into non-oiled and oiled reaches and calculated the land loss rates for each 10% increase in oil cover (e.g. 0% to >70%), to determine if land loss rates for each reach oiling category were significantly different before and after oiling. Finally, we calculated background land-loss rates to separate natural and oil-related erosion and land loss. Oiling caused significant increases in land losses, particularly along reaches of heavy oiling (>20% oil cover). For reaches with ≥20% oiling, land loss rates increased abruptly during the 2010-2013 period, and the loss rates during this period are significantly different from both the pre-oiling (p < 0.0001) and 2013-2016 post-oiling periods (p < 0.0001). The pre-oiling and 2013-2016 post-oiling periods exhibit no significant differences in land loss rates across oiled and non-oiled reaches (p = 0.557). We conclude that oiling increased land loss by more than 50%, but that land loss rates returned to background levels within 3-6 years after oiling, suggesting that oiling results in a large but temporary increase in land loss rates along the shoreline