Thienyl Sulfide

METHYL 2-THIENYL SULFIDE (Sulfide, methyl 2-thienyl) 

If the reaction does not start, it may be assisted by the addition of a small amount of methylmagnesium iodide in ethereal solution. 

The sulfur was distilled and then ground in a mortar before use. 

The mechanical stirring is continued. The sulfur dissolves during the refluxing period to give a clear yellow solution. A sludge which adheres to the bottom of the flask may form, but the yield is unaltered. 

On reheating, a vigorous reaction with the sulfur occurs. A means of cooling the reaction flask should be at hand to ensure control of the reaction. 

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The synthesis of dithieno[3,2-3 2, 3 -<7]thiophene 15a has also been accomplished using a combination of the methods described by De Jong et al. and Brandsma . In this approach, 3-bromothiophene 298 was lithiated and the 3-lithiothiophene 308 species reacted with sulfur dichloride to give di(3-thienyl)sulfide 309. Ring closure of 309 was effected using -butyllithium followed by addition of cupric chloride to yield dithieno[3,2-3 2, 3 -. 

Rearrangement of allyl 3-thienyl sulfide (45) gives 2-methyl-2,3-dihydrothieno[3,2- >]thiophene (46) [Eq. (21)]. 

The rearrangement of crotyl 2-thienyl sulfide (47) at 200° gave only 48, 49, and 2,3-dimethyl-2,3-dihydrothieno[2,3-6]thiophene (50) out of numerous possibilities. 

Thienyl sulfides with the 2-position of the thiophene ring blocked, e.g., allyl 2-methyl-3-thienyl sulfide (51), also undergo sigmatropic rearrangement when heated in quinoline [Eq. (23)]. 2,6-Dimethyl-2,3-dihydro-thieno[3,4-Z ]thiophene (52) is formed, together with other products. 

Synthesis. The first known thiophene-based metal dithiolenes were reported by Gol dfarb and Kalik in 1968." These consisted of the nickel and copper complexes of 2,3-thiophenedithiolate produced from ethyl 3-thienyl sulfide as shown in Scheme 1. Both complexes were reported as black, high melting solids and were thought to be the neutral bis(2,3-thiophenedithiolate) species. 

Methyl 2-thienyl sulfide has been prepared by the action of phosphorus trisulfide on dimethyl succinate 3 and by the action... 

Thiophene oligomers, preparation of 88H(27)1731. Thiophenecarboxylic acids and their derivatives 86HC(44,3)565. Thiophenethiols, thienyl sulfides, and related compounds 86HC-(44,3)135. 

Methyl-l-tetralone, 35,96 Methyl 2-thienyl sulfide, 35, 85 Methyl 0-tiiiodipropionate, 30, 65... 

We prepared di(l-alkynyl)sulfides, (RC==C)2S, in excellent yields by adding sulfur dichloride at very low temperatures to solutions of alkynyllithiums in Et20 [7]. Grignard derivatives gave poor results. In Chap. V and VI the successful preparation of di(thienyl)sulfides, di(furyl)sulfide and a di(aryl)sulflde are described, using THF as a solvent. All these reactions are extremely rapid and must be carried out at — 80 °C or lower in order to prevent the attack of SC12 on the product. 

Di(2-Furyl)Sulfide, Di(2-Thienyl)Sulfide and Di(3-Thienyl)SuIfide... 

Isomeric thienothiophenes can also be synthesized from other thiophene derivatives. In the study of the 3,3-sigmatropic rearrangement of allyl 2-thienyl sulfide (85), 2-methylthieno[2,3-Z)]thiophene (86) and 3-chloro-3,4-dihydro-2/f-thieno[2,3-Z)]thiopyran (87) were isolated in a total yield of up to 60% (77ZOR2624, 79KGS1062, 82DOK97). 

A mixture of thiophene and isomeric thienothiophenes (total yield of 85%) was prepared by the gas-phase reaction of dimethyl sulfide, diethyl disulfide, diethyl trisulfide and diethyl tetrasulfide with acetylene (89ZOR2588). It was also found that gaseous allyl 2-thienyl sulfide is transformed into a mixture of thiophene-2-thiol, bis(2-thienyl) sulfide and 2-methylthieno[2,3-i]thiophene at 350-410 °C in the presence of acetylene, the reaction gives these products along with thieno[2,3-i]thiophene (91KGS1312). Thermolysis (at 540 °C) of a mixture of di(prop-l-enyl) sulfide and 2-chloro(or bromo)thiophene affords a mixture of thieno[2,3-Z ]thiophene and thieno[3,2- )]thiophene (91ZOR354). 

Lithium intermediates served as the starting compounds in the synthesis of the corresponding 2(a)- or 3(p)-substituted derivatives of thienyl sulfides 153 and 154, thieno[2,3-Z)]thienyl sulfides 155 and 156 and thieno[2,3-Z)]thienylthieno[2,3-Z)]thio-phenes 157 and 158 (79BSB325). 

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