American Cyanamid Company

Murray Garber

David William Reger

Lawrence J Ross

Don Wesley Long

Walter Joseph Stepek

An improved method of preparing acid addition salts of dl 6-phenyl-2,3,5,6-tetrahydroimidazo[2,1-b]thiazole (dl-tetramisole) by reacting dl-3-(.beta.-hydroxyphenethyl)-2-iminothiazolidine or an acid-addition salt thereof, with a mixture of concentrated hydrochloric acid and concentrated sulfuric acid to obtain dl 3-(.beta.-chlorophenethyl)-2-iminothiazolidine acid-addition salt, treating this compound with aqueous alkali to obtain dl 6-phenyl-2,3,5,6-tetrahydroimidazo[2,1-b]thiazole free base, and converting the latter compound to dl 6-phenyl-2,3,5,6-tetrahydroimidazo [2,1-b]thiazole acid-addition salts in a highly purified state. The products are useful as anthelmintics.

Method of preparing dl

There is provided a fully integrated process for preparing a 2-dialkoxyphosphinylimino-1,3-dithietane in good overall yields with considerable savings in materials, time and labor involving a plurality of steps comprising the overall reaction of a dialkoxyphosphoryl chloride and an alkali metal or ammonium thiocyanate to obtain a dialkoxyphosphinyl isothiocyanate, reacting the latter with 1.1 to 1.2 molar equivalents of an alkali mercaptan in the presence of a water:acetone mixture (1:9 to 1:3), and finally reacting resultant dialkoxyphosphinyldithiocarbamate with methylene bromide or methylene iodide to obtain a 2-dialkoxyphosphylimino-1,3-dithietane.

Process for the preparation of the

There is provided a process for preparing 2-diethoxyphosphinylimino-1,3-dithietane by reacting diethoxyphosphinyldithiocarbamate with a methylene halide in an aqueous medium and in the presence of phase transfer catalyst whereby said dithietane is recovered in good yields.

Process for the preparation of 2-dialkoxy phosphinylimino-1,3-dithietane

There is provided a fully integrated process for preparing a 2-dialkoxyphosphinylimino-1,3-dithietane in good overall yields with considerable savings in materials, time and labor involving a plurality of steps comprising the overall reaction of a dialkoxyphosphoryl chloride and an alkali metal- or ammonium thiocyanate to obtain a dialkoxyphosphinyl isothiocyanate, reacting the latter with 1.1 to 1.2 molar equivalents of an alkali mercaptan in the presence of a water and, finally, reacting resultant dialkoxyphosphinyldithiocarbamate with methylene bromide or methylene iodide in the presence or absence of a non-ionic surfactant under controlled pH conditions ranging from 5 to 8 to obtain resultant 2-dialkoxyphosphinylimino-1,3-dithietane. The latter finds utility for the control of root-knot nematode.

Integrated process for the preparation of

There is provided a process for the preparation of 3,5-disubstituted pyrazoles which involves: A. the reaction of a methyl ketone, such as acetophenone or an appropriate derivative thereof, with an appropriate aldehyde, such as benzaldehyde in the presence of base to form a 1,3-disubstituted .alpha.,.beta.-unsaturated ketone, such as chalcone or a substituted chalcone, B. the acidification of said .alpha.,.beta.-unsaturated ketone, followed by treatment of the acidified reaction mixture with hydrazine to form a disubstituted pyrazoline, and C. the catalytic dehydrogenation of said pyrazoline to yield the desired 3,5-disubstituted pyrazole.

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Trenton, NJ, United States of America

Murray Garber