Isothiazolines

Chloro-a,/3-unsaturated aldehydes condense with ammonium thiocyanate to give isothiazoles (76EGP122249). 2,3-Diphenylcyclopropenone reacts with iV-sulfinyl-cyclohexylamine in the presence of nickel tetracarbonyl to give the isothiazolin-3-one 1-oxide (197) (79SST(5)345). Cholesteryl acetate reacts with trithiazyl trichloride in pyridine to give the isothiazolo steroid (198) (77JCS(P1)916). 

Isothiazolin-3-one, 2-methyl-biocide, 1, 399 4-Isothiazolin-3-one, 2-octyl-biocide, 1, 399 Isothi azolin-3-ones 1-oxide... 

Biocides Especially for controlling Clostridium and similar organisms found in water present in aviation kerosene and diesel tanks. Biocides include special grades of isothiazolines, polyquats, diamines, and sulfones. 

Figure 1-4. Pyrazol, isooxazol, isothiazol, 1,2-benzoisothiazolin-3-one, 4,5-dichloro-2-N-octyl-isothiazolin-3-one.

Dibromo-1 -chloro-4-thiocyanato-2-butene Isothiazolin-3-ones ... 

Ethylene glycol monoacetate 5-Chloro-2-methyl-4-isothiazolin-3-one or... 

Dichloro-2-N-octyl-isothiazolin-3-one and 2-methylthio-4-tert-butylamino-6-cyclopropylamino-S-triazine or N,N-dimethyl-N -phenyl-N -fluorodichloromethylthio)sulfamide Anthraquinones Free halogen sources with 5,5-dimethylhydantoin,... 

J. C. Hsu. Synergistic microbicidal combinations containing 3-isothiazoline and commercial biocides. Patent US 5190944, 1993. 

Although no single active agent meets all the requirements of the ideal wet-state paint antimicrobial, one biocide group stands out as being the "best we have" and those are products based on the isothiazolin-3-one structure (Figure 14). 

The combination of 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT) was described by Elsom in 1988 as probably the most cost effective biocide for industrial preservation. This combined product, along with the benzyl derivative (l,2-benzisothiazolin-3-one - BIT) either on their own or combined with other actives comprise the majority of modem wet-state biocides currently in use. 

Because the objective of this work was to assess the benefits of encapsulation, it was decided to opt for one structural class of biocide. The biocides selected for this purpose were based on the isothiazolinone structure. 2 Examples include 2-octyl-4-isothiazolin-3-one (OIT), 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT) (Figure 1). 

To probe interactions between active silanol sites and the isothiazolin-based biocides a number of model probes were investigated 12. The adsorbates (1-methylpyrro lidin-2-one, pyridine, pyrrolidine, pyrrole, 2-methylthiophene, 2-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-octyl-4-isothiazolin-3-one and 2-cyclopenen-l -one,) varied in basicity, polarity and 7i-character. The amounts of the adsorbates retained by... 

Another major chemistry often used are isothiazolinones. There are a number of different varieties of this chemistry, probably the most common form used is supplied as a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, (see Figure 5, usually in the ration of 3 1). 

The use of biocides is spread across the whole polymer range, e.g., paints, ropes, textiles, fibres, etc. Many are copper, silver or arsenic compounds and also various heterocyclic compounds, e.g., isothiazolines (which have some structural resemblance to penicillin). 

Sometimes, hydrogen sulfide converts an oxygen-containing heterocycle into a sulfur-containing one, and as furans and polycyclic furans are very common in nature such reactions may be the origin of the polycyclic thiophenes mentioned above. A typical example is the formation of the isothiazolin-3-thione (6) from the isoxazolin-3-thione (7) on treatment with hydrogen sulfide and hydrogen bromide.8... 

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