Cyanamide, comparison with

American Cyanamid has industrialized a process which limits the temperature rise. To do this, it uses a large excess of add (14 times the weight of benzene to be nitrated, instead of 3 in the conventional method). Under these conditions, the add absorbs the heat generated by the reaction, and the temperature does not exceed 145°C, thus preventing undesirable side conversions, but increasing the reaction rate in comparison with the conventional process. Before recycling, moreover, the add is concentrated at this temperature, with a slight additional heat input... 

The structure elucidation of the kinamycins was a formidable challenge, and the information presented below draws from the work of several research groups over a period of more than 20 years. As will be shown, the originally proposed structure of the kinamycins contained a cyanamide rather than a diazo function. Subsequent synthetic and biosynthetic studies led to replacement of the cyanamide with a diazo function. The structural elucidation was challenging, in part, because of the high degree of unsaturation of the kinamycins, which limits the utility of H and 2D NMR analysis. In addition, because these structures were unprecedented, there were no clear benchmarks for comparison at the time. The pathway from isolation to determination of the correct structure is described below. 

An interesting comparison of diazomethane, diazirine (5.59), cyanamide (5.60) and aminoisonitrile (5.57, A-isocyanamide) was conducted by Kroeker et al. (1991). They compared the experimental acidities of three of these compounds with... 

Of the 807,000 tons of nitrogen represented by the 5 6 per cent from die atmosphere, only 39,000 tons or less than 5 per cent was fixed by the arc process, 175,000 tons or less than 22 per cent was fixed according to the cyanamide process, while 593> o or over 73 per cent was fixed according to the direct synthetic ammonia process, A comparison of these figures with those for the previous year leaves no doubt of the trend of development. Of the 641,000 tons produced during the year ending June 30, 1926, the arc process ac-... 

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