Preparation of substantially dust-free tetrahydro-3,5-dimethyl-1,3,5-thiadiazine-2-thione granules
AssigneeBASF SE
InventorHeinz Appler
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Abstract
Substantially dust-free granules of tetrahydro-3,5-dimethyl-1,3,5-thiadiazine-2-thione (I) are prepared by reacting methylamine (II) with carbon disulfide (III) and formaldehyde (IV) or by reacting the methylammonium salt of N-methyldithiocarbamic acid (V) with formaldehyde (IV) by a process in which the reaction is carried out in the presence of at least one diaminoalkylene of the formula VI R.sup.1 -NH-A-NH-R.sup.2 VI where R.sup.1 and R.sup.2 independently of one another are each hydrogen or alkyl and A is an unsubstituted or substituted 1,2-ethylene, 1,3-propylene or 1,4-butylene bridge.
Claims10
A process for the preparation of substantially dust-free granules of tetrahydro-3,5-dimethyl-1,3,5-thiadiazine-2-thione (I) of the formula ##STR4## wherein said granules contain dimers or higher polymers of the active ingredient, in which two nitrogen atoms of the dimers or higher polymers not belonging to the same molecule I are linked to one another by a 1,2-ethylene, 1,3-propylene or 1,4-butylene bridge, which process comprises:
- reacting methylamine (II) and from 0.1 to 10 mol %, based on (II) of at least one diaminoalkylene of the formula VI
- R.sup.1 -NH-A-NH-R.sup.2 VI
- where R.sup.1 and R.sup.2 independently of one another are each hydrogen or C.sub.1 -C.sub.4 -alkyl and A is a 1,2-ethylene, 1,3-propylene or 1,4-butylene bridge, and these bridges may carry from one to four C.sub.1 -C.sub.4 -alkyl groups, with carbon disulfide (III) and formaldehyde (IV).
Dependencies are inferred from the claim text.