Azolones

Note that, despite a certain similarity in their names, neither the azolones nor the N-(N, N -dimethylaminosulfonyl)azoles are in any way related to the azole fungicides of the DMI type (see Chapter 17 of this book). 

Data for the three commercialized products of these types can be found in Tables 13.2.1 and 13.2.3. 

the fungicidal activity was detected and an optimization program carried out [88] that finally led after three years of work and the preparation of over 700 analogs [88b] to an optimized structure, famoxadone for patents see [89]. In-vivo structure-activity relationships have been reported with the oomycetes Phy-tophthora infestans and Plasmopara viticola [88]. Famoxadone was announced in 1996 as a broad spectrum fungicide for the control of diseases caused by Ascomy-cetes and Basidiomycetes in various crops and particularly against downy mildew diseases caused by oomycetes in potato, vines and vegetables [90]. 

Cyazofamid was announced [101] and then commercially introduced in 2001 as a fungicide for the control of late blight and downy mildews for the mode of action, see Ref [102]. Amisulbrom has been developed by Nissan for similar uses and entered official trials in Japan in 2003 [76]. 

Dimefluazole did not achieve commercial status, but this compound and an analog were the subject of a detailed investigation of the mode of action [103]. The conclusion was that the azole moiety acts as a leaving group, so that the sulfonyl group of the a.i. binds covalently to a nucleophile of the Qi-center of oomycetes [103]. The different submolecular target sites of cyazofamid and Qo-site inhibitors lead to lack of cross resistance. 

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The removal of a hydrogen atom from a heterocyclic nitrogen atom of azolones by nucleophiles acting as bases, e.g. (14) (15), gives mesomeric anions, e.g. (15) <-> (16) <->... 

Azolone anions are readily alkylated at nitrogen, e.g. 2-triazolone with methyl iodide gives the 1-methyl derivative. 

In benz- and phenyl-azolones, electrophilic substitution often occurs in the benzene ring such reactions are considered as reactions of substituents (see Sections 4.02.3.2.1 and 4.02.3.4.1). 

Oxidation to an azolone is an expected reaction for a pseudo base, but little appears to be known of such reactions. Most commonly, pseudo bases suffer ring fission. Estimated rates of ring-opening of (169) are in the ratio 10 10" 1 for X = O, S and NMe, respectively (79AHC(25)1). 

The photoisomerization of 3-hydroxyisoxazoles gave the corresponding 2-ox-azolones without the isolation of the azirine (Scheme 21) (67HCA137). Also in this case calculations are in agreement with the experimental results [99H(50)1115]. 

Chin-azolin, n. quinazoline. -azolon, n. quin-azolone. -dolin, n. quindoline. 

Vision)-comb. Vision)-comb. Azolone (Smith, Miller ... 

When ethyl acetoacetate is warmed with an equivalent quantity of phenyl-hydrazine, the compound (I), which is not a true hydrazone, is first formed this undergoes ring formation (II) with loss of ethyl alcohol upon further heating. The product (II) is N or l-phenyl-3-methyl-5-p)U azolone. 

The excellent solvent and migration fastness which is typical of all benzimid-azolone pigments probably results from this singular structural principle, which has not yet been discovered in any other azo pigment class. 

Most electrophilic carbenes, such as 2/f-imidazolylidenes and 3H- and 4i/-triazolylidenes, in nitrobenzene gave rise to deoxygenation processes involving the intermediacy of the ylide 42, which decomposed to ni-trosobenzene and 43 (Scheme 12). However, the azolones 43 are too unstable to be detected or trapped in the reaction conditions. 

Thermolytic reactions are known for all azolone structures (8)-(ll). Thermolysis may be regarded as a six-electron thermally allowed process and follows two major pathways, both extruding YCX or ZCX fragments (Scheme 2). 

Azolines of type (13) undergo thermal decomposition in an analogous way to that already discussed for azolones (see Section 4.14.5.2) (Scheme 19). Path (i) is followed by those azolines having Z = S and path (ii) by those with Z = O. Path (i) is a typical retro-1,3-dipolar cycloaddition process, via an intermediate nitrile sulfide, while path (ii) might involve an acyl (Y = Z = O) or thioacyl (Y = S, Z = O) nitrene intermediate (136), which in turn rearranges to iso(thio)cyanate. However, no systematic attempts to trap this possible nitrene intermediate seem to have been made, and so a concerted pathway for the fragmantation cannot be ruled out. 

A samrated 5(2//)-oxazolone, also known as a 3-oxazolin-5-one or a pseudox-azolone, can be considered as the tautomer of a saturated 5(4//)-oxazolone (or 2-oxazohn-5-one) by a 1,3-prototropic shift (Scheme 7.1). 

Treatment of 2-(l-adamantyl)glycine with TFAA gave 4-(l-adamantyl)-2-(tri-fluoromethyl)-5(477)-oxazolone in high yield. A 2-(trifluoromethyl)-5(477)-ox-azolone derived from serine has been obtained from 0-trimethylsilyl-A-(trifluoroacetyl)serine diethylamide. ... 

Pigment Orange 36 [12236-62-3] 11780 monoaZo benzimid- azolone coupling of diazotized 2-nitro-4-chloro-aniline with acetoacetyl-5-amino-benzimidazolone... 

All azolones 8-11 are susceptible to thermolytic reactions. There are two major pathways of thermolysis both involving extrusion of YCZ or XCZ fragments via a thermally allowed [a2s + + ff2s] process (Scheme 3). A general... 

Thermal decomposition of azolines of type 13 follows an analogous pathway to that already discussed for azolones (see Section 6.04.5.2). As depicted in Scheme 11, those azolines having X = S follow a typical retro-l,3-dipolar cycloaddition process (path a) affording carbonyl compounds and nitrile sulfide intermediates, which in the absence of a trapping... 

The reduction of the 1,2-double bond in a series of 7-chloro-6-sulfamyl-4(3//)-quinazolinones (110) by sodium borohydride in the presence of aluminum trichloride has been reported.138 Lithium aluminum hydride caused the conversion of 3-methyl-4(3/7)quin-azolone to 3-methyl-l,2,3,4-tetrahydroquinazoline.185a... 

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