7267-35-8Relevant academic research and scientific papers
Iodine-DMSO mediated conversion of Narylcyanothioformamides to Narylcyanoformamides and the unexpected formation of 2-cyanobenzothiazoles
Ahmed, Saleh A.,Al-Hindawi, Bassam,Al-Masri, Harbi Tomah,Alzamly, Ahmed,Judeh, Zaher M. A.,Moussa, Ziad,Rasool, Faisal,Saada, Sara
, p. 6133 - 6148 (2022/03/31)
Cyanoformamides are ubiquitous as useful components for assembling key intermediates and bioactive molecules. The development of an efficient and simple approach to this motif is a challenge. Herein, we demonstrate the effectiveness of the I2-DMSO oxidative system in the preparation of Narylcyanoformamides from N-arylcyanothioformamides. The synthetic method features mild conditions, broad substrate scope, and high reaction efficiency. Furthermore, this method provides an excellent entry to exclusively afford 2-cyanobenzothiazoles which are useful substrates to access new luciferin analogs. The structures of all new products were elucidated by multinuclear NMR spectroscopy and high accuracy mass spectral analysis. Crystal-structure determination by means of single-crystal X-ray diffraction was carried out on (4-bromophenyl)carbamoyl cyanide, 5,6-dimethoxybenzo[d]thiazole-2- carbonitrile, 5-(benzyloxy)benzo[d]oxazole-2-carbonitrile, 4,7-dimethoxybenzo[d]thiazole-2-carbonitrile, and (5-iodo-2,4-dimethoxyphenyl)carbamoyl cyanide, a key intermediate with mechanistic implications.
Synthesis of fused 1,2,4-dithiazines and 1,2,3,5-trithiazepines
Koyioni, Maria,Manoli, Maria,Koutentis, Panayiotis A.
, p. 9717 - 9727 (2015/02/19)
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).
Conversion of imino-1,2,3-dithiazoles into 2-cyanobenzothiazoles, cyanoimidoyl chlorides and diatomic sulfur
English, Russell F.,Rakitin, Oleg A.,Rees, Charles W.,Vlasova, Olga G.
, p. 201 - 205 (2007/10/03)
Primary aromatic amines condense with 4,5-dichloro-1,2,3-dithiazolium chloride 1 to give high yields of the N-aryl imines 2 which on heating give 2-cyanobenzothiazoles 3, thus providing a simple two-step route to these heterocycles from the appropriate aniline. This thermolysis is favoured by electron donating substituents in the aniline ring, and retarded by electron withdrawing groups in favour of a second pathway in which both dithiazole sulfur atoms are lost to form cyanoimidoyl chlorides 4. This is the sole pathway when both aniline ortho positions are substituted. Analogous N-alkyl imines 5, prepared from the salt 1 and the bis(trimethylsilyl) derivatives of the amine, also decompose with loss of both sulfur atoms as singlet diatomic sulfur, S2. 4-Chloro-5-methylimino-5H-1,2,3-diathiazole 5a does this at 140-150°C and the S2 generated is intercepted with 2,3-diphenylbutadiene, 2,3-dimethylbutadiene and norbornene to give 16a, 16b and 17 respectively.
