Synthesis of unsymmetrical arylthiophenes and bithienyls via oxidative cyclization of 1,3‐butadiene‐1‐thiols

Oxidative cyclization of 2-mercapto-5-aryl-2,4-pentadienoic acids with iodine produced the respective 5-aryl-2-thenoic acids. The method was also suitable for the synthesis of unsymmetrical substituted 2,2′-bithienyls, and 2,3′-bithienyls. The synthesis of 5-carboxy-2′-bromo-5′-phenyl-2,3′-bithienyl from benzal-acetone demonstrated that oxidative cyclization of 1,3-butadiene-1-thiols is a useful procedure for preparing 5′-aryl-2,3′-bithienyls from simple carbonyl compounds. Preferential ring bromination of 2-phenyl-4-methyl-thiophene with N-bromosuccinimide and a radical catalyst was also observed.

[1]  E. Campaigne,et al.  Benzo[b] thiophene derivatives. XXII. Synthesis of the isomeric 5-methyl-6-methoxy- and 5-methoxy-6-methylbenzo[b] thiophene-2-carboxylic acids† , 1975 .

[2]  F. Bohlmann,et al.  Polyacetylenverbindungen, CXXIV. Synthesen einiger natürlicher Schwefelacetylenverbindungen , 1967 .

[3]  E. Campaigne,et al.  The sulfur analog of serotonin. , 1967, Journal of medicinal chemistry.

[4]  S. Gronowitz,et al.  Bromination of 3-phenylthiophene , 1967 .

[5]  Paul E. Fanta,et al.  The Ullmann Synthesis of Biaryls, 1945-1963 , 1964 .

[6]  E. Campaigne,et al.  Sulfur Heterocycles from the Ring Closure of Bisarylalkyl Disulfides1,2 , 1964 .

[7]  H. Brown,et al.  A New Aldehyde Synthesis—The Reducti[UNK]on of Acid Chlorides by Lithium Tri-t-butoxyaluminohydride1 , 1958 .

[8]  H. Wynberg,et al.  The Synthesis of Di- and Terthienyls1,2 , 1957 .

[9]  E. Campaigne,et al.  The Use of Dimethylformamide as a Formylation Reagent1 , 1953 .

[10]  W. T. Caldwell.  The Synthesis of 2-Sulfanilamido-5-aminopyrimidine , 1951 .

[11]  Robert E. Miller,et al.  STUDIES ON THE CHEMISTRY OF HETEROCYCLICS. XII.1PREPARATION OF ACETYLENIC DERIVATIVES OF THIOPHENE , 1951 .

[12]  N. Chapman,et al.  Mechanism of oxidative ring closure of compounds of the buta-1,3-diene-1-thiol type with halogens to give thiophen derivatives , 1970 .

[13]  T. R. Seshadri,et al.  The structure of a new polythienyl from , 1966 .

[14]  F. Bohlmann,et al.  Polyacetylenverbindungen, LXIX. Die Acetylenverbindungen der Gattung Echinops L , 1965 .

[15]  M. Nishio,et al.  The Preparation and Geometrical Isomerism of Substituted α-Methylthio-cinnamic Acids , 1965 .

[16]  G. T. Phillips,et al.  1310. Naturally-occurring thiophens. Bithienyl derivatives from Tagetes minuta L. , 1965 .

[17]  J. H. Uhlenbroek,et al.  Investigations on nematicides: II. Structure of a second nematicidal principle isolated from Tagetes roots , 1959 .

[18]  E. Campaigne,et al.  A New Synthesis of Thiophenes and Condensed Thiophenes by Ring Closure of Disulfides1, 2 , 1956 .

[19]  R. Wizinger,et al.  Über den Vinylensprung bei unsymmetrischen Anisylmethinen , 1955 .

[20]  C. Bradsher,et al.  RHODANINE DERIVATIVES OF KETONES1 , 1950 .

[21]  E. Campaigne,et al.  3-Substituted thiophenes; antihistaminics of the N-(3-thenyl)-ethylenediamine series. , 1949, Journal of the American Chemical Society.

[22]  F. Straus.  Über die sog. Ketohalogenide ungesättigter Ketone und ihre Umsetzungsprodukte , 1912 .