Succinimide reactions

Derivatives of polyisobutylene (6. in Figure 9.1) offer the advantage of control over the molecular weight of the polyisobutylene obtained by cationic polymerization of isobutylene. Condensation on maleic anhydride can be done directly either by thermal activation ( ene-synthesis reaction) (2.1), or by chlorinated polyisobutylene intermediates (2.2). The condensation of the PIBSA on polyethylene polyamines leads to succinimides. Note that one can obtain mono- or disuccinimides. The mono-succinimides are used as... 

The third family (c. in Figure 9.1) less widespread, derived from the alkylphenols, offers as with the succinimides several possibilities of modification to the ratio of hydrophilic and lipophilic groups. Mannich s reaction of the alkyl-phenols also provides additives for lubricating oils. 

Fluorescein reaction. Fuse together in a dry test-tube o-i g. of succinimide, O l g. of resorcinol and 2 drops of cone. HjSOi, Cool, add water and then NaOH solution in excess. A green fluorescent solution is obtained. 

P-Naphthaldehyde. This preparation illustrates the use of -bromo-succinimide (Section VI.26) in the conversion of the readily available P-methylnaphthalene into 2-bromomethylnaphthalene and of the latter into p-naphthaldehyde by the Sommelet reaction. 

Antisyphilitics. Mercuric sahcyiate/T77(9-72-/] (6) and mercuric succinimide [584 3-0] (7) are simple salts prepared by the reaction ia water of mercuric oxide and sahcyhc acid or succinimide, respectively. Use as antisyphilitics has been substantially eliminated by virtue of the discovery of more potent and effective nonmetaUic biocides. 

Reactions with Nitrogen Compounds. Succinimide [123-56-8] mp 126°C, can be prepared by reaction of aqueous solutions of the acid with ammonia (105) or urea (106) (eq. 7). The solution is heated until water and ammonia are no longer evolved and the molten cmde succinimide is purified by fractionation. Alternatively, the cmde product can be recrystaUized from water (105). 

Halogen-substituted succinimides are a class of products with important appHcations. /V-Bromosuccinimide [128-08-5] mp 176—177°C, is the most important product ia this group, and is prepared by addition of bromine to a cold aqueous solution of succinimide (110,111) or by reaction of succinimide with NaBr02 iu the presence of HBr (112). It is used as a bromination and oxidation agent ia the synthesis of cortisone and other hormones. By its use it is possible to obtain selective bromine substitution at methylene groups adjacent to double bonds without addition reactions to the double bond (113). 

Although connection of polyalkylene or poly(alkylene oxide) groups to the polyamine is most commonly by the succinimide linkage, a different linking group is employed in another important class of ashless dispersants— the Mannich bases. They are prepared on a commercial scale by reaction of an alkylphenol with formaldehyde and a polyamine (173—177). The alkyl and polyamine moieties are similar to those used in the succinimide products. 

The substitution reactions of 3-acetamidothiophene have been extensively investigated. From the bromination with A-bromosuc-cinimide and from the chlorination with sulfuryl chloride or A-chloro-succinimide only the 2-isomers were obtained, the structure of which... 

The isoxazole nucleus is also halogenated in the 4-position by N-bromosuccinimide provided there is no substituent in this position. This reaction does not proceed homolytically, as might have been expected, and appears to represent a simple electrophilic substitution by the bromine cation. Similar cases have been previously described for the bromination of certain aromatic compounds with A -bromo-succinimide. ... 

In a more recent study on 1,3-dipolar cycloaddition reactions the use of succi-nimide instead of the oxazolidinone auxiliary was introduced (Scheme 6.19) [58]. The succinimide derivatives 24a,b are more reactive towards the 1,3-dipolar cycloaddition reaction with nitrone la and the reaction proceeds in the absence of a catalyst. In the presence of TiCl2-TADDOLate catalyst 23a (5 mol%) the reaction of la with 24a proceeds at -20 to -10 °C, and after conversion of the unstable succinimide adduct into the amide derivative, the corresponding product 25 was obtained in an endojexo ratio of <5 >95. Additionally, the enantioselectivity of the reaction of 72% ee is also an improvement compared to the analogous reaction of the oxazolidinone derivative 19. Similar improvements were obtained in reactions of other related nitrones with 24a and b. 

It has been more difficult to obtain the exo isomer in the above described reaction. Application of the TiCl2-TADDOLate complex induced fair exo selectivity and up to 60% ee. This was improved by the application of succinimide as an auxiliary for the alkene. This approach has been the only entry to a highly exo selective reaction and up to 72% ee of the exo isomer was obtained. In the Pd(BF4)2-BI-NAP-catalyzed reaction which gave mixtures of the endo and exo isomers, high ee of up to 93% was in a single case obtained for the minor exo isomer. In one case it was also observed that a Zn(OTf)2-BOX complex induced some exo selectivity and up to 82% ee of the exo isomer. 

Schlenk equilibrium 93 s-cis 7, 9, 26, 31, 35 sdyl-substituted 16 Simmons-Smith reaction 87 SnClj 309 SnCU 309 solid-phase 198 square bipyramidal 255 rr-stacking 8 stannyl-substituted 16 s-trans 7, 26 - acrolein 307 succinimide 227 sulfonamides 122 synchronicity 306... 

The free-radical chain reaction may also be terminated by coupling of two carbon-radical species. As solvent carbon tetrachloride is commonly used, where the A-bromosuccinimide is badly soluble. Progress of reaction is then indicated by the decrease of the amount of precipitated NBS and the formation of the succinimide that floats on the surface of the organic liquid layer. 

The cyclized analog of meralluride is prepared by a similar synthesis. Thus, condensation of camphoric acid (42) (obtained by oxidation of camphor) with ammonia gives the bicyclic succinimide (44). Reaction with allyl isocyanate followed by ring opening and then reaction with mercuric acetate affords the mercury derivative (45) as the acetate rather than the hydroxide as above. Reaction with sodium chloride converts that acetate to the halide (46). Displacement on mercury with the disodium salt of thioglycollic acid affords the diuretic mercaptomerine (47). ... 

Problem 10.6 The major product of the reaction of methvlenecyclohexane with jV-bromo-succinimide is l-(bromomethyl)cyclohexene. Explain. 

Simple alkyl halides can be prepared by radical halogenation of alkanes, but mixtures of products usually result. The reactivity order of alkanes toward halogenation is identical to the stability order of radicals R3C- > R2CH- > RCH2-. Alkyl halides can also be prepared from alkenes by reaction with /V-bromo-succinimide (NBS) to give the product of allylic bromination. The NBS bromi-nation of alkenes takes place through an intermediate allylic radical, which is stabilized by resonance. 

Succinic anhydride yields the cyclic imide succinimide when heated with ammonium chloride at 200 °C. Propose a mechanism for this reaction. Why do you suppose such a high reaction temperature is required ... 

The reaction scheme is rather complex also in the case of the oxidation of o-xylene (41a, 87a), of the oxidative dehydrogenation of n-butenes over bismuth-molybdenum catalyst (87b), or of ethylbenzene on aluminum oxide catalysts (87c), in the hydrogenolysis of glucose (87d) over Ni-kieselguhr or of n-butane on a nickel on silica catalyst (87e), and in the hydrogenation of succinimide in isopropyl alcohol on Ni-Al2Oa catalyst (87f) or of acetophenone on Rh-Al203 catalyst (87g). Decomposition of n-and sec-butyl acetates on synthetic zeolites accompanied by the isomerization of the formed butenes has also been the subject of a kinetic study (87h). 

B. 2H-Pyran-2-one. A mixture of 9.81 g. (0.100 mole) of 5,6-dihydro-2/I-pyran-2-one, 200 mg. of benzoyl peroxide, 18.6 g. (0.105 mole) of A-bromosuccinimide [2,5-Pyrrolidinedione, 1-bromo-] (Note 7), and 800 ml. of carbon tetrachloride is prepared in a 2-1., three-necked, round-bottomed flask equipped with a reflux condenser and a mechanical stirrer. The resulting suspension is stirred and heated to reflux. After 1.5 hours at reflux, most of the solid is dissolved, and the solution gives a negative test with starch-iodide paper. The reaction mixture is then allowed to cool, dining which time succinimide [2,5-Pyrrolidine-dione] crystallizes out. The precipitate is removed by filtration, and the filtrate is concentrated under reduced pressure to leave crude 5-bromo-5,6 -dihy dro 211 -pyran-2 one [ 211 Py ran - 2-one, 5-bromo-5,6-dihydro] as an oil. 

This reaction is analogous to 10-16. Primary and secondary alcohols can be converted to alkyl aryl sulfides (ROH RSAr) in high yields by treatment with BU3P and an V-(arylthio)succinimide in benzene. Thioethers RSR can be prepared from an alcohol ROH and a halide R Cl by treatment with tetra-methylthiourea Me2NC(=S)NMe2 followed by NaH. ... 

The suspension may be warmed to dissolve the alkene more rapidly. (E)-Stilbene dissolves completely at ca. 65°. If the suspension is warmed, it must be cooled below 30° before proceeding further to prevent a vigorous reaction when the N-bromo-succinimide is added. The submitters recommend that the warm suspension be cooled under an atmosphere of nitrogen. If a volatile alkene is used, the mixture should be cooled prior to and during the addition of N-bromosuccinimide to prevent losses by evaporation. 

Succinimide is readily silylated by HMDS 2 to the N-silylated product 201, which seems, however, to be in equilibrium with the O-silylated derivative 202 a (cf the closely related reactive center in persilylated uridine 3) and reacts after 6-10 days at 24 °C with one equivalent of primary or secondary amines such as morpholine to give the crystalline colorless cyclic acylamidine 203 and HMDSO 7, even in the absence of any protective gas [33] (Scheme 4.12). The reaction is much faster on heating to 120 °C under argon. At these temperatures 201 and 202 a, and possibly also the acylamidine 203, are apparently partially O-silylated by HMDS 2 to the very sensitive 2,5-bis(trimethylsilyloxy)pyrrole 202b or to 2-tri-... 

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