Tetrasulfur-tetranitride

The strongly exothermic process is carried out in an inert organic solvent by reacting NH3 with a solution (of known concentration) of CI3 in S3CI3. 

The reaction is carried out in a six-liter round-bottom flask with a three-hole cork stopper. The stopper holds a large-diameter inlet tube reachii as far down into the flask as possible the tube has a T connection at the top through which a wire can be pushed to remove any plugs that may form. The inlet tube is connected with an NH3 cylinder via a flow meter, a pressure release valve, and a long KOH drying tube. The reaction flask is also provided with a power-driven stirrer and a reflux condenser topped with a KOH drying tube. 

Four liters of CCI4 (dried over PaOg) and 250 ml. of SgClg are placed in the flask. This solution is first saturated with CI3 at room temperature then a fast stream of NH3 (about 50 liters/hour) is passed through with vigorous stirring. The reaction temperature may not exceed 30-50°C if necessary, the flask should be cooled with ice water. 

It must be kept in mind during the entire procedure that is susceptible to explosive decomposition Induced by shock or temperatures above 100°C. 

Light yellow-orange solid at ordinary temperature becomes light yellow at —30°C on heating to 100°C, orange-red. M.p. 178°C, b.p. about 185°C decomposes explosively on further heating d 2.22. 

Submitted by Milaghos Villbna-Blanco and Wiluam L. Jolly Checked by B. Zane EoANf and Ralph A. ZiNOABof 

Caution. The substance prepared in this synthesis is explosive. 

Tetrasulfur tetranitride can be prepared in good yield by the method described by Becke-Goehring. In this revision of the method those points are emphasized which, if neglected, can cause difficulty. Because S4N4 is explosive, and because the large amounts of material involved in the earlier method are unwieldy, the synthesis has been scaled 

As long as the reaction mixture is at ambient temperatures or higher, there is no harm in passing an excess of ammonia gas through the mixture. The yields of S4N4 and S7NH are unaffected by the passage of excess ammonia. 

The preliminary chlorination of sulfur (I) chloride to sulfur(II) chloride may be omitted, if desired, but the total yield of S4N4 is thereby reduced by a factor of 2. If S7NH is sought, the chlorination must be omitted, because only 

Submitted by A. MAANINEN, J. SIIVARI, R. S. LAITINEN, and T. CHIVERS+ Checked by J. D. LAWRENCE and T. B. RAUCHFUSS  

Tetrasulfur-tetranitride (S4N4) (Fig. 1) is widely used as a starting material for the preparation of other cyclic and acyclic SN derivatives. The standard 

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The only heterocyclic seven-membered ring system with maximum unsaturation containing six heteroatoms is 1,3A4,5,2,4,6-trithiatriazepine (1). The methoxycarbonyl derivative 2 is a minor product (14%) of the complex reaction of tetrasulfur tetranitride with dimethyl acetylenedicarboxylatc in refluxing toluene, which gives mainly dimethyl l,2,5-thiadiazole-3,4-dicarboxylate (3, 67%) (see Houben-Wcyl, Vol. E8d, pl54ff which includes an experimental procedure). Two other products are the trithiadiazepine 4 (5%, see Section 4.4.1.1.1.) and the 1,2,4-thiadiazole derivative 5 (3%).385... 

The yield of the ester 2 in the reaction of tetrasulfur tetranitride with dimethyl acetylenedicarb-oxylate is increased if the reaction is conducted at lower temperatures. The ester is transformed into the parent trithiatriazepine 1 by hydrolysis, followed by decarboxylation of the resulting acid.417... 

As in the case of Group IVA, combinations with these typical non-metals will not be treated in detail insofar as nitrogen compounds are concerned. Of interest with respect to this review are the highly conducting compounds that are obtained by the room-temperature reaction of tetrasulfur tetranitride with halogens, e.g., (SNBrg4)j. (1, 366,423). 

The polyazapolysulfur ring system 1,3,2,4,6-dithiatriazine 15 is obtained by reacting 1-aryl-2,2,2-trifluoroethanone oximes with tetrasulfur tetranitride in refluxing toluene. However, the yield is only moderate <%JHC295>. 

See Disulfur dinitride Metal chlorides Tetrasulfur tetranitride Metal chlorides... 

Like tetrasulfur tetranitride, salts of trisulfur trinitride and of pentasulfur tetran-itride (particularly alkali-metal salts) are heat- and friction-sensitive explosives. Preparation on a scale limited to 1 g, and care in use of spatulae or in preparation of samples for IR examination is recommended. 

H. Tetrasulfur Tetranitride and Related Sulfur-Nitrogen Compounds... 

Tetrasulfur tetranitride, S4N4 has a structure that can be considered as a hybrid of the following two resonance structures ... 

Because nitrogen compounds of Se and Te are much less important than those of sulfur, this section will be devoted to the sulfur compounds. The binary compounds containing sulfur and nitrogen have several unusual structures and properties that make them an interesting series. Probably the most studied compound of this type is S4N4, tetrasulfur tetranitride, which is prepared by the following reactions ... 

The 1,4-diketone 1,2-dibenzoylethane 151 can be transformed in one step into 3,4-dibenzoyl-l,2,5-thiadiazole 152 when treated either with preformed trithiazyl trichloride in tetrachloromethane (Equation 29) <1997J(P1)2831> or with urethane, thionyl chloride, and pyridine in benzene (Katz reagent) <2002ARK90> (see also Section 5.09.9.2.l(iii)(b)). Similarly, treatment of 1,3-diketones 153 with tetrasulfur tetranitride antimony pentachloride complex in toluene at 100 °C < 1998J(P 1 )2175 >, or trithiazyl trichloride in boiling tetrachloromethane < 1997J(P 1)2831 >, affords 4-substituted-3-aroyl-l,2,5-thiadiazoles 154 (Equation 30). 

Aroylformamido-4-aryl-l,2,5-thiadiazoles 156 can also be prepared from aryl dibromomethyl ketones 155 on treatment with tetrasulfur tetranitride at 115 °C (Equation 31) <1995J(P1)253>. These reactions are, however, complex, and the 1,2,4-thiadiazole 157 is often produced as a minor product. 

No mechanistic discussion was offered and the proposed conversion of 1,2,5-thiadiazole 156 into 1,2,4-thiadiazole 157 with MCPBA <1995J(P1)253> was incorrect, the error caused by incompletely purified 1,2,5-thiadiazole <1999JHC515>. In contrast, monohalogenated methyl aryl ketones gave 1,2,4-thiadiazoles 157 with tetrasulfur tetranitride in chlorobenzene at 110-115 °C <1992JHC1433>. 

The treatment of aliphatic monoamines, benzil monooxime, benzil monohydrazone, and alkyl, monohaloalkyl arylketoximes bearing two or three a-hydrogens with tetrasulfur tetranitride to afford 1,2,5-thiadiazoles was presented in CHEC(1984) and CHEC-II(1996). 

Enamines 187 with electron-withdrawing groups in the /3-position are converted into thiadiazoles 188 in moderate yields (50-60%) on treatment with either tetrasulfur tetranitride antimony pentachloride complex <2000H(53)159> or trithiazyl trichloride <2001J(P1)662> (Equation 38 Table 12). Cyclization onto electrophilic /3-substituents was not observed, and thus the procedure offers a regiospecific synthesis of 4-substituted-3-aroyl-l,2,5-thiadiazoles. 

Unlike the reaction of alkyl aryl ketoximes with tetrasulfur tetranitride <1996CHEC-II(4)355>, the treatment of alkyl methyl ketoximes 189 with tetrasulfur tetranitride antimony pentachloride complex in either benzene or toluene at 50-80°C gave low yields (3-37%) of 3-alkyl-4-methyl-l,2,5-thiadiazoles 190 (Equation 39) <1999H(50)147>. Compounds 190 were volatile and the low yields are in part attributed to their loss as the solvent was removed in vacuo. Suprisingly, only single regioisomers were obtained. 3-Heptanone oxime 191 did, however, give a mixture of two isomers 192 and 193 (Equation 40). 

In a development on the reaction of monohaloalkyl aryl ketoximes with tetrasulfur tetranitride, the introduction of two halogens such as chlorine, bromine, or fluorine at the a-position of alkyl aryl ketoximes significantly improved the yields of thiadiazoles <1998J(P1)109>. The preferential displacement of chlorine over bromine or fluorine allowed the preparation of monobromo- and monofluoro-3-aryl-thiadiazoles 195 from a,a-chlorobromoalkyl- and a,a-chlorofluoro-alkyl aryl ketoximes 194 (Equation 41). 

The reaction of active hydrocarbons, phenols, and related compounds with tetrasulfur tetranitride affords fused thiadiazoles, and this chemistry is well documented in CHEC(1984) <1984CHEC(6)513> and CHEC-II(1996) <1996CHEC-II(4)355>. No recent work has been reported. 

In combination with the use of tetrasulfur tetranitride, trithiazyl trichloride, or any equivalent source of N-S-N , the technique of functionalizing a two-carbon source such as active methylene, alkene, or alkyne into thiadiazole (see Section 5.09.9.1.4) followed by reduction (see Section 5.09.5.6) provides a rapid route to 1,2-diamines. 

Tetrasulfur tetranitride (9a) adopts a cage structure with equal S-N bond lengths (1.62 A) and two weak transannular S- -S interactions of ca. 2.60 A at room temperature. Tetraselenium tetranitride and the hybrid l,5-Se2S2N4 also have similar structures (9b, 10).54 Rietveld analysis indicates that S4N4 undergoes a transition to a new orthorhombic phase at 397 K.55... 

Reactions of arylchloromethyl-p-tolyl sulfoxides with tetrasulfur tetranitride (S4N4) yield 3,5-diaryl-1,2,4,6-thiatriazine 1-oxides <00T7153>. [4+2] Cycloadditions of thiazyl... 

Strontium azide, 4785 Styrene, 2945 Tetracyanoethylene, 2629 Tetraethyllead, 3095 Tetramethyl-2-tetrazene, 1759 Tetrasulfur tetranitride, 4770... 

Tetratellurium tetranitride, 4773 Tetrasulfur dinitride, 4755 Tetrasulfur tetranitride, 4770 Thallium(I) nitride, 4731... 

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