Process for the manufacture of sulfonylaminocarbonyl triazolinones and salts thereof

#The present invention relates to a process for manufacturing sulfonylaminocarbonyl triazolinones and salts thereof, which are herbicidally active compounds, wherein the intermediate product of the process is not isolated. In particular, this invention relates to the conversion of a substituted triazolinone to a sulfonylaminocarbonyl triazolinone, and without the isolation of this intermediate product, the sulfonylaminocarbonyl triazolinone is then converted to a salt thereof.

#In a preferred embodiment of the invention, 5-methoxy-4-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (MMT) is converted to 4,5-dihydro-3-methoxy-4-methyl-5-oxo-N-[[2-(trifluoromethoxy)phenyl]sul fonyl]-1H-1,2,4-triazole-1-carboxamide (MSU), and without isolating the MSU intermediate product, the MSU is converted to a salt thereof. Further, in another preferred embodiment of the invention, 5-propoxy-4-methyl-1,4-dihydro-3H-1,2,4-triazol-3-one (PMT) is converted to 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-propoxy-1H-1,2,4-traizol-1-yl)carbon yl]amino]sulfonyl]-benzoic acid methyl ester (PSU), and without isolating the PSU intermediate product, the PSU is converted to a salt thereof.

#Sulfonylaminocarbonyl triazolinones are well known in the art, as are processes for their preparation and use as herbicides. European Patent EP-A 341,489 discloses certain substituted sulfonylaminocarbonyl triazolinones having herbicidal properties. Further, U.S. Pat. Nos. 5,534,486 and 5,869,681 describe a process for producing sulfonylaminocarbonyl triazolinones which are bonded by oxygen. The process includes the reaction of a triazolinone with a sulfonamide derivative. U.S. Pat. No. 5,750,718 describes intermediates for herbicidal sulfonylaminocarbonyl triazolinones having substituents which are bonded by sulfur.

#The Preparation of MKH 6562 Hydrate

#About 261.0 grams (1.74 moles) of 98% pure 5-methoxy-4-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (MMT) hydrate in about 2600 grams of methyl isobutyl ketone (MIBK) were dried by azeotropic distillation of part of the MIBK under reduced pressure (with a pot temperature of about 80.degree. C.), and then cooled to room temperature under a nitrogen atmosphere. To the resulting MMT slurry in MIBK was added about 534.0 grams (1.74 moles) of 87% pure 2-(trifluoromethoxy) benzenesulfonyl isocyanate over a period of about 2 hours. The reaction mixture was stirred at room temperature for about 6 hours. The conversion reaction of the MMT was monitored using a liquid chromatograph. About 140.0 grams of water were added to the reaction mixture. The mixture was then treated with 50% aqueous sodium hydroxide (NaOH) until the reaction was complete. The reaction mixture was stirred for about 1 hour, filtered, washed with about 500 grams of MIBK and dried to isolate the MKH 6562 hydrate. The yield of MKH 6562 hydrate was 719.9 grams (i.e., 93% yield based on MMT hydrate) and the purity was 98% (as hydrate).

#The Preparation of MKH 6561