e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
The insertion and extrusion of heterosulfur bridges. XIII. Syntheses and structural studies of nitrophenanthro [4, 5??bcd] thiophenes
…, MP Stevens, JJ Lu, CE Klopfenstein
Index: Klemm, L. H.; Tsuchiya, Reiko; Wong, Eric K. L.; Stevens, Michael P.; Lu, Jennifer J.; Klopfenstein, C. E. Journal of Heterocyclic Chemistry, 1987 , vol. 24, p. 357 - 360
Abstract A simplified procedure for sulfur bridging of phenanthrene (2a) with hydrogen sulfide and a catalyst, but without solvent, is described. The product, phenanthro [4, 5-bcd] thiophene (1a), undergoes nitration at 25 or 60 in acetic anhydride to give mixtures (56– 79%) of 1-nitro-1a and 3-nitro-1a in varying ratios. Reductive acetylation of these nitro derivatives gives 1-and 3-acetylamino-1a (93% and 33%). Hydrodesulfurization of the ...