Richter Gedeon Vegyeszeti Gyar Rt

Astra Aktiebolag

Aktiebolaget Astra

Ferenc Morasz

Dezso Korbonits

Pal Kiss

Gergely Heja

Endre Palosi

Ida Szvoboda Nee Kanzel

Csaba Gonczi

Laszlo Ledniczky

Csaba Huszar

Attila Nemeth

Erzsebet Szalay

Erzsebet Molnar Nee Bako

Ferenc Sperber

Karoly Ban

Istvan Bone

Gyorgy Mihalovics

Karol Gyure

Erzsebet Szabo Nee Kardos

Sandor Garaczy

Kalman Harsanyi

Gyorgy Fekete

Bela Hegedus

Lajos Toldy

Tibor Balogh

Gyorgy Domany

Endre Kasztreiner

Jozsef Reiter

Tibor Lang

Eva Againe Csongor

Janos Borvendeg

Margit Bidlo Nee Igloy

Arpad Lazar

Andras Rado

Mihaly Sut

Peter Gyri

Ildiko Buttkai

Arpad Kvari

Tibor Somogyi

Oszkar Fuchs

Mihaly Su

Iidiko Buttkai

Arpad K Vari

Peter Gy Ri

Process for the preparation of 4-methyl-5-(2-chloroethyl)-thiazole and

The present invention relates to a process for the preparation of compounds of general formula (I), wherein R stands for a straight chained C.sub.1-5 alkyl group substituted by a chlorine atom in the 2-position, and acid addition salts thereof, characterized by reacting a 3,5-dichloro-2-alkanone of general formula (V), wherein R is a defined above, with an inorganic thiocyamate, and a) converting the 3-thiocyanato-5-chloro-2-alkanone of general formula (IV), thus obtained, wherein R is as defined above, into 2-chloro-4-methyl-5-(2-chloroalkyl)-thiazole of general formula (II), wherein R is as defined above, by gaseous hydrochloric acid in an organic solvent, hydrogenating the said compound in the presence of a metal catalyst in an organic solvent, or b) reacting said compound of general formula (IV) with an aqueous mineral acid and treating the 2-hydroxy-4-methyl-5-(2-chloroalkyl)-thiazole of general formula (III), thus obtained with a halogenating agent, and hydrogenating the 2-chloro-4-methyl-5-(2-chloroalkyl)-thiazole of general formula (II) thus obtained, wherein R is as defined above, in an organic solvent in presence of a metal catalyst, and optionally converting the 4-methyl-5-(2-chloroalkyl)-thiazole of general formula (I), wherein R is as defined above, thus obtained or a hydrochloride salt thereof, in a manner known per into another acid addition salt or setting free a compound of general formula (I), wherein R is a defined above, from its acid addition salt.

The invention relates to the new monohydrate of N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N'-cyanoguanidi ne (cimetidine), a histamine-H.sub.2 receptor antagonist which is called N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N'-cyanoguanidi ne H (cimetidine H) as well as to a process for the preparation of same, which comprises pouring a hot, homogeneous aqueous solution of N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N'-cyanoguanidi ne, optionally containing also methylamine, onto ice and separating the N-methyl-N'-{2-[(5-methylimidazol-4-yl)-methylthio]-ethyl}-N'-cyanoguanidi ne monohydrate.

Cimetidine monohydrate

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Ferenc Morasz