P. R. Huddleston

A Convenient Synthesis of 2-Substituted 3-Hydroxy- and 3-Amino-Thiophens from Derivatives of 2-Chloroacrylic Acid

Abstract A valuable synthesis of methyl 3-amino-1 and 3-hydroxy-2 2-thiophen carboxylates, due to Fiesselmann, involves the base-induced condensation of methyl thioglycollate with 2,3-dihalogeno-propionitrile and 2,3-dihalogenopropionate esters, respectively. It seemed to us that readily accessible 2-halogenoacrylic acid derivatives might be useful substitutes for the halogenated compounds previously employed in these reactions. Accordingly we have used compounds (1a) and (1b) in a modification of the Fiesselmann process, and have obtained good yields of the thiophen derivatives (2a) and (2b):-

Mannich Reactions of Methoxythiophens

Abstract As far as we are aware no genuine Mannich reaction of the thiophen nucleus has been reported. A Mannich-like reaction of thiophen, formaldehyde and ammonium chloride or hydroxylamine salts has been described by Hartough and his co-workers 1–4 but the reaction failed with amines (eg morpholine). It is well known that the more electron rich nuclei of pyrrole 5 and indole6 undergo the reaction. It seemed to us that the introduction of an electron-releasing group into the thiophen ring might increase its reactivity to a similar level, and this has proved to be the case.

DEHALOGENATION OF 1-HALOTHIENYLDI- AND -TETRAHYDROISOQUINOLINES BY SODIUM METHOXIDE IN DIMETHYL SULFOXIDE

Int. Cl. ... A61K31/505; A61K31/44; A61K31/47; A61K31/38 U.S. Cl. ......................... 514/259; 514/340; 514/345; 514/349; 514/312; 514/311; 514/313; 514/314; 514/269; 514/309; 514/307: 514/444; 514/445; 514/.447; 514/249; 514/248; 514/252; 514/375 Field of Search ..................................... 514/259,340, 514/345, 349, 312, 311, 313, 314, 269, 309, 307, 444, 445, 447, 249, 248,252, 375

Thienopyridines. Part 7. Some Electrophilic Substitution Reactions of Thieno[2,3-b]- and -[3,2-b]pyridine Isosteres of 4-Oxygenated and 2,4-Dioxygenated Quinolines.

Reactions de bromation, nitration et diethylaminomethylation des hydroxy-4-, dihydro-4,7 methyl-7 oxo-4- et hydroxy-4 dihydro-6,7 oxo-6 thieno [2,3-b] pyridines et des dihydro-4,7 oxo-7-, dihydro-4,7 methyl-4 oxo-7- et dihydro-4,5 hydroxy-7 oxo-5 thieno [3,2-b] pyridines