The results of a number of screening experiments are reported that were designed to seek hydrogen donor molecules that function as high-temperature stabilizers (i.e., >400 °C) in jet fuels and similar hydrocarbon mixtures. The most important conclusion of this work was that in the temperature range between 400 and 450 °C, 1,2,3,4-tetrahydroquinoline (THQ) was by far the best thermal stabilizer that we have discovered to date and significantly more effective than benzyl alcohol (BzOH), our previous benchmark.

Synthetic procedures have been developed which lead to the 2-aza congeners 3 and several related N-oxides 4. The analogues 3 exhibited a wide range of in vitro cytotoxicity against L1210 leukemia, the human colon adenocarcinoma cell line LoVo, and the doxorubicin resistant LoVo/DX cell line. Selected analogues of 3 showed significant P388 antileukemic activity in mice with 3c exhibiting high activity. This activity was also retained in the related N-oxide 4a. These heterocyclic bioisosteric models are representative of the first anthracene-9,10-diones which display antileukemic activity comparable to mitoxantrone.

We have previously demonstrated that additives such as benzyl alcohol and the like successfully retard the formation of carbonaceous materials in jet fuels at temperatures in excess of 400 "C. An understanding of the underlying mechanisms is important and could point the way to the design of superior additives. Here we report the results of thermal stressing studies performed on a model system consisting of dodecane/benzyl alcohol mixtures. Dodecane has been the subject of many prior studies and is a good representative model compound for jet fuel. Furthermore, deuterated compounds of both dodecane and benzyl alcohol are available and results obtained using these compounds were found to be particularly useful in rationalizing why benzyl alcohol acts as a thermal stabilizer in hydrocarbon mixtures at such high temperatures.

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