Ureas sulfonyl-, hydrolysis

Plants. Degraded rapidly. DT50 1.5-4.5 days main metabolic pathways were hydrolysis of the sulfonyl urea bridge to form the pyridine sulfonamide and pyrimidine amine, and hydroxylation on the pyrimidine ring... 

Oxo-3-pyrazolin-4-sulfonic acids (Table XXXVI) are prepared by direct sulfonation738,745 with sulfuric acid and acetic anhydride or by chlorosulfonation with chlorosulfonic acid, followed by hydrolysis to the acid.1248,1249 The reaction of 2,3-dimethyl-l-phenyl-5-oxo-3-pyrazolin-4-sulfonyl chloride with urea forms a bis(5-oxo-2-pyrazolin-4-sulfonic acid) derivative,1249 the only such bis derivative reported. Reduction of the sulfonic acid chlorides with zinc and acid forms the corresponding mercapto compound.1249... 

The sulfonyl urea herbicide rimsulfuron that is degraded increasingly rapidly at pHs from 5 to 9 the main degradation pathway is by rearrangement of the sulfonyl urea group followed by hydrolysis (Schneiders et al. 1993) (Figure 4.21). 

Compound (2) is acidic and exhibited both electrophilic and nucleophilic properties <79H(6)815). The pyridothiatriazinone (2) is readily soluble in dilute aqueous sodium bicarbonate forming its sodium salt, which undergoes slow hydrolysis to urea (9) via (8) (Scheme 2). The electrophilic nature of the sulfonyl group in (2) was demonstrated by its reaction with morpholine to give (10) (Equation... 

Four types of adsorbents are usually shared by SPE applications to herbicides. Hydrophobic modified silica materials (CIS, C8, C2, Cl) are extensively used for a large variety of samples (biological samples such as serum and urine for atrazine, simazine, prometryne, ametryn, sulfonyl ureas, or environmental samples such as different types of waters for alachlor, aldicarb, methiocarb - with concomitant hydrolysis -, medium polar, neutral, and alkaline herbicides, phenyl ureas). 

Sulfonyl diisocyanates, such as m-phenylenedisulfonyl diisocyanate, are used as monomers for base-soluble polymers (15). 4-Isocyanatobenzenesulfonyl isocyanate can also be used as a monomer for base-soluble polymers. Reaction of p-toluenesulfonyl isocyanate with polymers having amide units in the backbone structure affords sulfonyl urea derivatives, which on hydrolysis with 1 N NaOH degrade the polymer to carboxylic acids (16). Likewise, polymerization of the monomer derived from acrylamide and p-toluenesulfonyl isocyanate affords a homopolymer, which on hydrolysis with 1 N NaOH affords polyCacrylic acid) (17). 

These analogs were not appreciably different in herbicidal activity than the N-oxides themselves, and both were only somewhat less active than the corresponding sulfonyl-ureas of the parent series. This suggests the possibility that bicyclic analogs 44 might act as pro-herbicides in that hydrolysis catalyzed within plant cells could result in the active uncyclized form, although this has not been proven by experiment. 

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