1-oxide reaction with acid anhydrides

EXPLOSION and FIRE CONCERNS highly flammable liquid NFPA rating Health 2, Flammability 4, Reactivity 2 oxidizes readily in air to unstable peroxides that may explode spontaneously condensation reaction with acid anhydrides, alcohols, ketones, and phenols can be violent combination with bromine, chlorine, fluorine, or iodine can be violent reaction of anhydrous ammonia, hydrogen cyanide, or hydrogen sulfide can be violent use carbon dioxide, dry chemical powder, or appropriate foam for firefighting purposes. 

The process to manufacture the perylene chromophore is basically unchanged since its discovery in the early 1900s. The reaction sequence begins with catalyzed air oxidation of a coal tar extract, acenaphthene (2), to produce naphthalic acid anhydride (3). There are several catalysts, such as V2OS, that are used Commercially in this oxidation reaction. Naphthahc acid anhydride is available from several global suppliers in a range of purities. 

Somewhat milder oxidative conditions lead to loss of but one carbon. Periodic acid cleavage of the side chain in 65, leads to the so-called etio acid (66). Reaction with propionic anhydride leads to acylation of the 17-hydroxyl group (67). Possibilities for neighboring group participation severely limit the methods available for activating the acid for esterification. Best results seemed to have been obtained by use of a mixed anhydride from treatment with diphenyl chloro-... 

N-Nitroso N phenylglycine, 46, 96 reaction with acetic anhydride to yield 3 phenylsydnone, 46, 96 Nitrosyl chloride, addition to bicyclo-[2 2 ljhepta 2,5 diene, 46, 75 2,4-Nonanedione, 47, 92 Nonane, 1,1,3 trichloro-, 46,104 Nortricyclanol, 46, 74 oxidation by chromic acid, 46, 78 Nortricyclanone, 46, 77 Nortncj clyl acetate 46, 74 frombicyclo[2 2 ljhepta 2,5 dieneand acetic acid, 46, 74 saponification of, 46, 75... 

Furthermore reactions with difluorophosphoric anhydride are of some importance (55). The easy cleavage of the P—0—P-bridge in reactions with organometallic oxides (17) and halides (18) leads to derivatives of difluorophosphoric acid in a very mild way ... 

Utilizing Wenkert s cyclization process, a number of new approaches have been elaborated for the synthesis of simple indolo[2,3-a]quinolizine derivatives. For example, treatment of JV-[2-(indol-3-yl)ethyl]piperidine (V-oxide (134) with trifluoroacetic anhydride gave piperideinium intermediate 135 in a Polonovski-type reaction, which could be cyclized in acidic medium to ( )-l (101). 

Beccalli et al. reported a new synthesis of staurosporinone (293) from 3-cyano-3-(lH-indol-3-yl)-2-oxo propionic acid ethyl ester (1464) (790). The reaction of 1464 with ethyl chlorocarbonate and triethylamine afforded the compound 1465, which, on treatment with dimethylamine, led to the corresponding hydroxy derivative 1466. The triflate 1467 was prepared from 1466 by reaction with trifluoromethanesulfonic anhydride (Tf20) in the presence of ethyldiisopropylamine. The palladium(O)-catalyzed cross-coupling of the triflate 1467 with the 3-(tributylstannyl)indole 1468 afforded the vinylindole 1469 in 89% yield. Deprotection of both nitrogen atoms with sodium ethoxide in ethanol to 1470, followed by photocyclization in the presence of iodine as the oxidizing agent provided the indolocarbazole 1471. Finally, reductive cyclization of 1471 with sodium borohydride-cobaltous chloride led to staurosporinone (293) in 40% yield (790) (Scheme 5.248). 

Compound 264 is unexpectedly stable against light, but can easily be oxidized to the sulfoxide 265 and the sulfone 266. Sulfoxide 265 can be isolated and a-activated by reaction with acetic anhydride (Scheme 4.46). a-Acetoxylated tetrahydrothio-phene 267 has 0,S-acetal-like reactivity and can be functionalized with various alcohols or thiols under acid catalysis with camphorsulfonic acid (CSA) (268). 

A-Acyloxypyridinium salts can be isolated from the reaction of A-oxides with acid anhydride by the inclusion of a strong acid possessing a non-nucleophilic anion, e.g. HCIO4. Such acids will protonate the initially formed carboxylate ion and provide a stable anion for salt formation (Scheme 115) (65JOC1909). 

Citronellol undergoes the typical reactions of primary alcohols. Compared with geraniol, which contains one more double bond, citronellol is relatively stable. Citronellol is converted into citronellal by dehydrogenation or oxidation hydrogenation yields 3,7-dimethyloctan-l-ol. Citronellyl esters are easily prepared by esterification with acid anhydrides. 

With tin vanadates, the selectivity for the formation of butadiene goes through a maximum at an atomic ratio Sn/V = 9. Below this ratio, the acidity is greater, leading to more maleic acid anhydride in the reaction products. Butadiene will adsorb more with increasing acidity and will have a greater opportunity to be oxidized. The resulting acid anhydride will desorb relatively easily from an acid catalyst. A basic catalyst will result in more combustion products. 

Oxidation of 1,2,5-trithiepine 44 with ///-chloroperoxybenzoic acid in CHCI3 resulted in the formation of crystalline monosulfoxide 130, which underwent Pummerer rearrangement upon reaction with acetic anhydride to furnish 6,7-dihydro[l,2,5]trithiepin 45 (Scheme 31) <1997JOC2432>. 

Monoetherification of polyols.12 Monobenzylation and monoallylation of polyols can be conducted conveniently under mild conditions by conversion to the stannylene derivative (dimeric) by di-n-butyltin oxide (5, 189 9, 141). The stannylene is then treated with benzyl bromide or allyl bromide and tetra-n-butylammonium iodide (1 equiv.) in benzene. The same conditions can be used to prepare monomethoxymethyl ethers. Quaternary ammonium bromides are less efficient catalysts than the iodides. These salts also accelerate reaction of stannylenes with acid anhydrides. The mechanism for this activation is not clear it may involve coordination of I" to tin. 

The reactions of tin oxides and alkoxides fall into two categories cleavage reactions and addition reactions. Cleavage or substitution reactions include reactions with acidic protic reagents, including amides (equation 93), thiols (equation 94), and acyl chlorides or anhydrides (equation 95). Addition reactions occur with heterocumulenes (equations 96 and 97). 

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