OXIDATIVE AND SYNTHETIC STUDIES OF THIOUREAS AND RELATED COMPOUNDS

Abstract

The thesis divided Into two parts,deals with <1) the oxldatlv* studies oa substituted thlouree* aad (11) the syntheses of various substituted thioureas and guanidlne derivatives* Oxidation of S,S« *elphcmyl»,g,M' ->dl-e-tolyl- and S,H,« dl*p-tolyl« thioureas were carried out with bromine and thionyl chloride in indifferent solvent a*dla Ilk* chloroform* The related substituted bls«for*a«Aeiae-dlsuiphido salts were isolated es the initial product of oxidation* Thee* disuiphida salts decoaposed quickly in the presence of moisture* In ethanol or •thanol-bensene mixtur* they were more stable and extruded slowly sa atom of elemental sulphur forming the related bis* femamidine-aonosuiFhlde salts* These too were very unstable substances and in etbenollc medium they isomerised lata the correspondingly substituted amidino thioureas. Oa farther oxidation these amidino thioureas afforded the final oxidation products, vis., bansothiaxoiyl guanidlne derivatives (t&gorshefVs baaes). la ionising medium also, the intermediate product,vis., subsUtuted aonosulphlde salts, have baaa Isolated by uslag iasttffielent quantity of bromine and modifying th* nature of the solveat aeatum* The aonosulphlde salts thus produced were identified by direct comparison aad uad*pia*sed mixed melting points with the corresponding products obtained from bisformamldlne disulphide salts* It he* been found also possible to syatheslse the above mentioned substituted bls^r*m^ane-*»aa*ulpbid* s*lt* by th* interaction of appropriate carbodilmldes with the corresponding thioureas in cold acetone medlam.in th* presence of hydrochloric or hydjobromic maids* Tk*** aoaosulphidas war* found idenUcal with the other monosulphides obtained by the oxidation of thioureas* la the ease of alkyi substituted thloureas,*-butyland »,«»**dibutyl- thioureas were oxidised with bromine mad thlonyl chlorld** Here also the Intermediat* produaU vis., the subsUtuted formemldlne bisulphides, monosulphide* and also the amidlnothioureas have been isolated* The** amidino thioureas oa farther oxldatt©a,foll©w*d ay basifleatlon affrded new bases, which were assigned the 3-butyl-lsdno-4Mmtyl-5-imia©«i,2,4« thladiasolldlne structures* The oxidation of 8-b*nsoyl-3-phenylthiourea with bromine in chloroform aad ethanol medium was carried out. The related Ms-foraasdaliie-di8ulphid*,ssM»9Sulphld* and the final oxidation product hav* been Isolated aad their chemistry Finally a possible mechanis* of the formation of various products as Isolated la these oxidations is also discussed* Second part of th* thesis deals with the synthesis of various M-alkyl (ary1-8-amidinothiourea hydrochlorides. The** were prepared by the condensation of aryleysnaxddos with the appropriate thioureas* Some of these compounds war* screened for biological activity and the testing results Indicate that they possess some antithyroid activity. Sea* H-substituted-** • benaeaesulphonyl thiourea* ware prepared by the aetloa af various amines on beaseaesulphcnyl Isothiocyanata. These eoapoumas war* prepared with a view that they might prove to be anti thyroidal agents. ff-aryi-lf'^-Csubstituted thlasolyl/naph«x»thiaxolyl/ beesothlaxelyl) thiourea* war* prepared by the condensation of various arylisothiocyanetes with tha aaproprliit* thiasolee, aaphthothiaxoles sad beaxothlasoles* These thioureas wham treated with ethanoU* ajsmonla la the pr*e*ne* of yellow lead oxide afforded the corresponding guenldinee* It has alee been found passible to synthesis* thes* substituted guanldines by the condensBttcm of aryleyeaamides with appropriate thiaacles, naphthothlaxoles aad bonaothlaaoles* Some of these subsUtuted thioureas aad guanldines possess analgesla.anUmalarlal aad antihyper tensive properties*