Reaction of 1,2-benzodithiole-3-thione with ethylene- and trimethylenediamines

摘要

1974 869Reaction of 1,2-Benzodithiole-3-thione with Ethylene- and Trimethylene-d iami nesBy Joseph Patrick Brown, Nickell Laboratories, Monsanto Chemicals Ltd., Cefn Mawr, WrexhamIn contrast to its reactions with rnonoarnines, in which only one of its sulphur atoms is displaced, 1.2-benzodithiole-3-thione can react with ethylene- and trimethylene-diarnines with displacement of two sulphur atoms ; theproducts are probably o-rnercaptophenyl-substituted nitrogen heterocycles.BOSHAGEN and his co-workers found that aliphaticamines react with 1 ,Z-benzodithiole-3-thione to givetwo series of interconvertible isomeric products : 1,2-benzoisothiazoline-3-thiones (1) and 1,Z-benzodithiol-3-imines (2). No reports of compounds from reactionof two inolecules of amine with one of the thione havebeen seen, so it was therefore expected that ethylene-diamine would react with two molecules of thioneto give the bis-compound (3), or its isomer (4).Infact, unchanged thione was recovered from the reactionand, together with a little of the expected bis-compound,a yellow compound, C,HloN2S, was also isolated,evidently formed from one molecule of diamine andone molecule of thione, with loss of one molecule ofhydrogen sulphide and one atom of sulphur.( 3 )H(5)The mass spectrum of the compound suggested theabsence of C=S and the possible presence of SH. Then.m.r. spectrum was not helpful; different types ofnon-aromatic protons could not be distinguished.Fhe i.r. spectrum indicated an NH group but there wasno prominent band attributable to SH.The compoundwas soluble in hot water, the yellow solution instan-taneously becoming colourless on acidification andalmost colourless on basification. Structure (5; R =H. Boshagen, H. Feltkamp, and W. Geiger, Ber., 1967, 100,2436; A. Baruffini, P. Borgna, and L. Amoretti, I1 Farmaco,1968, 28, 674.H) is therefore tentatively suggested rather than thecorresponding tricyclic benzoisothiazoline structureoriginally favoured. The bicyclic structure was sug-gested by Dr. D. Leaver,2 who postulates the illustratedmode of formation of this compound (see Scheme) andof a homologue, CloH,,N2S, with similar properties(except for differences in the i.r. spectrum, which in-clude a prominent band attributed to SH) which hasbeen made from trimethylenediamine.Both homo-lopes react additively with one molecular proportionof ethyl iodide. There is no band attributable to SHSCHEMEin the i.r. spectrum of either product. The simplestinterpretation is that S-alkylation has occurred in eachcase, so that the products are bicyclic, i.e. the hydriodideof compound ( 5 ; R = Et) and the correspondingtetrahydropyrimidine.EXPERIMENTALReaction of 1,2-BenzodithioZe-3-thione with Ethyle9aedi-amine.-A mixture of the thione (9.2 g), ethylenediamine(1.5 g), and ethanol (60 ml) was boiled for 4 h, then cooled,and the solid (6.4 g) was filtered off and slurried with warmbenzene (50 ml) for 10 min to remove unchanged thione.The undissolved material was recrystallised from ethanolto give crude 2-o-mercapto~henyE-Aha-imidazoZine (5 ; R = H)(1.05 g) . Recrystallisation from dimethylformamide gavebronze-yellow plates, m.p.244' (Found: C, 61.0; H, 5.6;N, 15.9; S, 17.0. C,H,,N,S requires C, 60-7; H, 5.6; N,15-7; S, 18.0), vm, (Nujol) 3200-3000, 1590, 1565,1415, 1286, 1100, 1058, 725, and 664 cm-l, m/e 178 (Mf).A little ethanol-insoluble material was recrystallised fromdimethylformamide to give NN'-bis- (1,2-benzodithioZ-3-yZ-idene)ethyZenediamine (4) as bronze-yellow needles (0- 19 g) ,m.p. 233-234" (Found: C, 53.3; H, 3.5; N, 7.9; S, 34-9.CIsH,,N,S requires C, 53-3; H, 3.3; N, 7.8; S, 35-6),v,, (Nujol) 2865, 1605, 1440, 1292, 1012, 758, and 715cm-l.Repetition of the experiment with twice the amount ofD.Leaver, Chemistry Department, University of Edin-burgh, personal communication870 J.C.S. Perkin Iethylenediamiiie gave a high yield (6-9 g) of compound(5). Use of a large excess of boiling diamine in the absenceof soIvent gave an intractable, brown gum.Reaction of 1,2-BenzodithioZe-3-thione with Trimethylene-diamine.-A solution of the thione (4.56 g) in benzene(40 ml) was treated with trimethylenediamine (1.03 ml),added in five portions on successive days. After two moredays, the benzene solution was decanted from a browngum and evaporated. Recrystallisation of the residuefrom ethanol gave yellow prisms (0.56 g), m.p. 210-220"of the 1,4,5,6-tetrahyd~o-2-o-mercaptophenyl~yrimidine(Found: C, 62-2; H, 6.3; N , 14.6; S, 16.7.C1,Hl,N,Srequires C , 62.5; H, 6.3; N , 1 4 4 ; S , 16.7), vmx. (KBr)3150, 3045, 2610, 1600, 1320, 1044, and 737 cm-', m/e192 (M+).Reaction of tlze Mercapto-cornPoupids with Ethyl Iodide.-The imidazoline (0.5 g), partly dissolved in boiling ethanol(10 ml), was treated with ethyl iodide ( 1 ml). The restof the starting material rapidly dissolved. After 3 minboiling, the solution was concentrated to yield, on cooling,cream plates (0.48 g), m.p. 185-189" of the hydriodide of2-o-ethylthiophenyl- Aa-imidazoline (Found : C, 39-5 ; €3, 4.7 ;N , 8.4. C,,H,,IN,S requires C, 39.5; H, 4.5; N , 84),v- 3000, 1605, 1580, 1475, 1360, 1280, 1030, 988, 763,730, and 650br cm-l. Similarly, the tetrahydropyrimidine(0.17 g ) yielded the hydriodzde of 2-o-ethylthiophenyZ-lJ4,5,6-tetrahydropyrimidine (0.08 g), m.p. 185" (Found: C, 41.2;H, 4.9; N, 7.9. C,,H1,1N2S requires C, 41-1; H, 4.9;N, 8.00,/,), Urn. 3120, 3000, 1630, 1610, 1425, 1315, 1200,970, 766, and 732 cm-l.I thank Dr. T. B. Gay and Mrs. J. Ellis for help with theinterpretation of spectra.3/2215 Received, 29th October, 1973