Aktiebolaget Astra

Peter Gy Ri

Dezso Korbonits

Pal Kiss

Gergely Heja

Endre Palosi

Ida Szvoboda Nee Kanzel

Csaba Gonczi

Csaba Huszar

Laszlo Ledniczky

Erzsebet Szalay

Erzsebet Molnar Nee Bako

Attila Nemeth

Istvan Bone

Ferenc Sperber

Ferenc Morasz

Karoly Ban

Erzsebet Szabo Nee Kardos

Sandor Garaczy

Gyorgy Mihalovics

Karol Gyure

Iidiko Buttkai

Arpad K Vari

Mihaly Su

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.

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

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Budapest, Hungary

Peter Gy Ri