Synthesis of fused 1,2,4-dithiazines and 1,2,3,5-trithiazepines
AuthorKoyioni, Maria G.
Koutentis, Panayiotis Andreas
SourceJournal of Organic Chemistry
Google Scholar check
MetadataShow full item record
Reacting ( Z)-N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)-1H-pyrazol-5-amines 5 with Et2NH and then with concd H2SO4 gives 5H-pyrazolo[3,4-e ][1,2,4]dithiazine-3-carbonitriles 7 in good yields (74-85%) and 6H-pyrazolo-[3,4-f][1,2,3,5]trithiazepine-4-carbonitriles 9 as minor products (0-6%). Furthermore, the 1,3-dimethylpyrazole analogue 5a was transformed into the dithiazine 7a in two discrete steps, allowing the isolation of a disulfide intermediate (Z)-2-[(diethylamino)disulfan-yl]-2-[(1H-pyrazol-5-yl)imino]-acetonitrile (8a). The one-pot, two-step reaction also worked with electron-rich hydroxy- and methoxy-substituted anilines. Thermolysis of the pyrazolo[3,4-e][1,2,4]dithiazines 7 gave the ring-contracted 1H-pyrazolo[3,4-d]thiazole-5-carbonitriles 6 (94-100%). With active sulfur, 1,3-dimethyl-5H-pyrazolo[3,4-e ][1,2,4]dithiazine-3-carbonitrile (7a) gave 1,3-dimethyl-6Hpyrazolo[3,4-f][1,2,3,5]trithiazepine-4-carbonitrile (9a), but on prolonged reaction times, it gave 5,7-dimethyl-5H-[1,2,3]-dithiazolo[4,5-b]pyrazolo[3,4-e][1,4]thiazine (13). Finally, in the absence of acid, heating a solution of (Z)-2-[(diethylamino)-disulfanyl]-2-[(1,3-dimethyl-1H-pyrazol-5-yl)imino]acetonitrile (8a) gave 4,6,10,12-tetramethyl-6H-pyrazolo[3,4-f]pyrazolo-[3′,4′:4,5]pyrimido[6,1-d][1,2,3,5]trithiazepine-8,12 b(10H)-dicarbonitrile (19) (67%). (Chemical Equation Presented). © 2014 American Chemical Society.
Showing items related by title, author, creator and subject.
Christoforou, Irene C.; Kalogirou, Andreas S.; Koutentis, Panayiotis Andreas (2009)Treatment of 1,2-bis(4-chloro-5H-1,2,3-dithiazol-5-ylidene)hydrazine 4 with benzyltriethylammonium iodide (1 equiv) affords dicyano-1,3,4-thiadiazole 3 and 5-cyano-1,3,4-thiadiazole-2-carboxamide 5 in 79 and 21% yields, ...
Photochemistry of an azido-functionalized cryptand: Controlling the reactivity of an extremely long-lived singlet aryl nitrene by complexation to alkali cations Bucher, G.; Tönshoff, C.; Nicolaïdes, Andrew N. (2005)Photolysis of the cryptand 1, bearing an intraannular azido substituent, results in a complex photochemistry. Low-temperature photolysis yields the triplet nitrene 32, which has been characterized by EPR spectroscopy. Small ...
Qualitative and quantitative determination of COPs in cypriot meat samples using HPLC determination of the most effective sample preparation procedure Georgiou, Christiana A.; Kapnissi‐Christodoulou, Constantina P. (2013)This research work describes the development of a fast high-performance liquid chromatography method for the simultaneous determination of five important cholesterol oxidation products (COPs). The influence of various ...