Synthesis of N-aryl-1,5,3-dithiazepanes and N-aryl-1,5,3-dithiazocanes in the presence of samarium- and cobalt-containing catalysts

Abstract

Efficient procedures were developed for the synthesis of N-aryl-1,5,3-dithiazepanes and N-aryl-1,5,3-dithiazocanes by cyclocondensation of anilines with formaldehyde and α,ω-dithiols (etane-1,2-dithiol and propane-1,3-dithiol), as well as by transamination of N-tert-butyl-1,5,3-dithiazepane or N-tert-butyl-1,5,3-di-thiazocane with aromatic amines in the presence of samarium and cobalt complexes.One of the most widely known and simplest procedures for the synthesis of practically important [1-3] heterocycles of the dithiazinane series is based on classical [4] cyclocondensation of primary amines with hydrogen sulfide and formaldehyde [5][6][7][8][9][10]. Published data on the synthesis of bicyclic [11][12][13][14][15] and N-substituted dithiazepanes [16,17] are considerably scantier. Ito and Sekiya [16] reported on the synthesis of N-hydroxy-1,5,3-dithiazepane (I) by cyclocondensation of hydroxylamine hydrochloride with ethane-1,2-dithiol and formaldehyde. Another approach to the synthesis of dithiazepane II is based on recyclization of 5-tert-butylhexahydro-1,3,5-triazin-2-one with ethane-1,2-dithiol in the presence of BF 3 · 2 HOAc [17] (Scheme 1). There are almost no data on preparative procedures for the synthesis of N-aryl-1,5,3-dithiazepanes and N-aryl-1,5,3-dithiazocanes.Taking into account the data of [16,17], we tried to synthesize N-aryl-1,5,3-dithiazepanes and N-aryl-1,5,3-dithiazocanes by cyclocondensation of primary aromatic amines with formaldehyde and α,ω-dithiols (ethane-1,2-dithiol and propane-1,3-dithiol). We examined in detail the effects of the solvent nature, reactant ratio, temperature, and reaction time on the yield of cyclocondensation products from aniline, formaldehyde, and ethane-1,2-dithiol. Aniline reacted with CH 2 O and ethane1,2-dithiol at a molar ratio of 1 : 2 : 1 in chloroform at 20°C to give ~65% of N-phenyl-1,5,3-dithiazepane (IIIa) in 6 h (Scheme 2). With a view to improve the yield of IIIa, the reaction was carried out in the presence of Cu, Co, Mn, Ti, Hf, V, Fe, Sm, and Ni salts and complexes, which were used by us previously [18] to catalyze the synthesis of N-substituted 1,3,5-dithiazinanes. Among the examined catalysts, only Sm(NO 3 ) 3 · 6 H 2 O ensured formation of heterocycle IIIa in 88% yield in 0.5 h (see table). Therefore, all subsequent heterocyclizations of anilines with formaldehyde and ethane-1,2-dithiol were carried out in the presence of 5 mol % of Sm(NO 3 ) 3 · 6 H 2 O as catalyst.Under analogous conditions [5 mol % of Sm(NO 3 ) 3 · 6 H 2 O, 20°C, 0.5 h, CHCl 3 as solvent] heterocycliza-

N-Substituted Derivatives of the Azadithiolate Cofactor from the [FeFe] Hydrogenases: Stability and Complexation

“…In contrast, related compounds are stable when SH is replaced by S-alkyl 27,28 or when the spacer between the thiol and the amine is extended, as is the case for cysteamine derivatives (R 2 NCH 2 CH 2 SH). 27 When the N-substituent is electron-withdrawing, the corresponding dithiolates appear more stable.…”

Samarium(III) nitrate-catalyzed one-pot synthesis of 42-membered N,S,O-containing cyclophanes

“…As a continuation of the research into catalytic synthesis of heterocyclic compounds [36][37][38][39][40][41][42][43][44] and to develop a selective route to 42-…”

Efficient catalytic method for the synthesis of N-aryl-substituted 1,5,3-dithiazamacroheterocycles

“…The reaction mixture was stirred at w20 C for 5 h and concentrated, and the residue was chromatographed on a column with SiO 2 to isolate pure heterocyclic products. 5,. Colorless oil (0.212 g, 89%), n D 20 1.6169; d H (400 MHz, CDCl 3 , 25 C) 1.59e1.62 (4H, m, CH 2 CH 2 ), 2.47e2.50 (4H, m, (SCH 2 )), 4.65 (4H, s, SCH 2 N), 6.77e6.90 (3H,m,Ph),7.28e7.31 (2H,m,Ph); d C (100 MHz, CDCl 3 , 25 C) 28.5 (CH 2 CH 2 ), 30.9 (SCH 2 ), 53.9 (SCH 2 N), 115.9,129.2,119.7,147.2 (Ph); MALDI TOF, m/z: 240.282 [MÀH] þ .…”

“…Catalytic heterocyclization of primary alkyl(aryl, hetaryl) amines, substituted hydrazines and hydrazides is an efficient method for selective synthesis of new N-substituted dithiazinanes, 1,2 dithiazepanes, 3e12 dithiazocanes, 5,7,8 dioxazepanes, 6 and dioxazocanes, 6 which are promising as biologically active compounds, 13e18 selective sorbents, and extractants for noble and precious metals. 19 Before our studies, no data on the synthesis of Nsubstituted 1,5,3-dithiazonanes, 1,5,3-dithiazecanes, 1,5,3-dithiazacycloundecanes, or N-aryl-1,11-dioxa-4,8-dithia-6-azacyclotridecanes were available from the literature.…”