Succinic anhydride activation

On the other hand, polymeric carriers can also be modified to introduce reactive groups. Polysaccharides such as dextran and inulin may be activated [149] by periodate oxidation to create aldehyde groups, by succinic anhydride activation to create carboxylic groups, or by p-nitrophenyl chloroformate activation to create reactive ester groups. 

Succinic anhydride activation. Carboxylic groups can be easily introduced in polysaccharides (P-OH) by reaction with succinic anhydride (III). They can then be transformed into reactive esters and finally coupled with drugs ... 

All lation. Maleic anhydride reacts with alkene and aromatic substrates having a C—H bond activated by a,P-unsaturation or an adjacent aromatic resonance (31,32) to produce the following succinic anhydride derivatives. 

Succinic acid is absorbed from aqueous solutions by anion-exchange resins or active carbon (9—11). Succinic anhydride forms rhombic pyramidal or bipyramidal crystals. It is relatively insoluble in ether, but soluble in boiling chloroform and ethyl acetate. Succinic anhydride reacts with water and alcohols, giving the acid and monoesters, respectively. 

Halogenation. Succinic acid and succinic anhydride react with halogens through the active methylene groups. Succinic acid heated in a closed vessel at 100°C with bromine yields 2,3-dibromosuccinic acid almost quantitatively. The yield is reduced in the presence of excess water as a result of the formation of brominated hydrocarbons. The anhydride gives the mono- or dibromo derivative, depending on the equivalents of bromine used. 

Succinic anhydride is extremely irritating to the eyes. It causes skin, mucous membranes, and respiratory tract irritation. It may be a sensiti2er. There is no evidence of carcinogenic activity in male or female tats given 50 or 100 mg/kg succinic anhydride (186) the Ames test is negative (187). LD q in rat 1510 mg/kg. There ate no estabflshed exposure limits for ACGIH TLV or TWA. 

Disconnecting the lactone gives hydroxyacid (48), With succinic anhydride In mind as an available 1,4-dl-carbonyl starting material, we can write keto acid (49) as an intermediate and the orientation is then correct for a Frledel-Crafts disconnection as both MeO and He activate this position. 

Five immobilization matrices have been tested and compared. These include a dextran layer on the sensor surface, succinic anhydride modified surface, monomer glutaraldehyde activated surface, polyglutaraldehyde activated surface and strepta-vidine/biotinylated antibody coated surface. 

Mitsubishi have reported several processes based on Ru-catalyzed hydrogenation of anhydrides and acids. Succinic anhydride can be converted into mixtures of 1,4-butane-diol and y-butyrolactone using [Ru(acac)3]/trioctylphosphine and an activator (often a phosphonic acid) [97]. Relatively high temperatures are required ( 200°C) for this reaction. The lactone can be prepared selectively under the appropriate reaction conditions, and a process has been developed for isolating the products and recycling the ruthenium catalyst [98-100]. 

This procedure is based upon a study 1 of the method outlined in the patent literature.2 The procedure is a general one and may be used for the condensation of succinic anhydride with naphthalene and with the mono- and dimethylnaphthalenes, although in no other case are the purification and separation of isomers so easily accomplished. In this particular type of condensation, as well as in certain other types of Friedel-Crafts reactions, nitrobenzene is far superior to the solvents which are more frequently employed. This is partly because of its great solvent power and partly because it forms a molecular compound with aluminum chloride, and so decreases the activity of the catalyst in promoting side reactions. 

Figure 6.7 Reaction of wood with succinic anhydride (SA) and subsequent reaction of the activated surface with hexamethylene diamine (HMDA), using diisopropyl carbodiimide (DIPCI) as a reaction promoter.

The synthesis of a water-soluble diphenylmethano-bridged fullerene 122 was achieved by hydrolyzing the bis (acetamide) 121 with acetic acid-aqueous hydrochloric acid and then converting it into the bis(succinamide) 122 by treatment with succinic anhydride (Scheme 4.25) [158]. Compound 122 is soluble in water at pH > 7. This is an important requirement for the investigation of the biological activity of fullerenes. Remarkably, 122 is an inhibitor for the HIV enzymes protease (HIV-P) and reverse transcriptase (HIV-RT) [159]. As suggested by molecular modeling. 

Groups of reportedly photochromic systems which deserve further study include (a) disulfoxides (123,124), (b) hydrazones (125-129), (c) osazones (130-133), (d ) semicarbazones (134-143), (e) stilbene derivatives (144), (/) succinic anhydrides (145-148), and (g) various dyes (149,150). A number of individual compounds also remain unclassified as to their mechanism of photochromic activity. These include o-nitro-benzylidine isonicotinic acid hydrazide (151), 2,3-epoxy-2-ethyl-3-phenyl-1-indanone (152), p-diethyl- and p-dimethyl-aminophenyli-minocamphor (153), brucine salts of bromo- and chloro-nitromethionic acid (154), diphenacyldiphenylmethane (155,156), 2,4,4,6-tetraphenyl-1,4,-dihydropyridine (155,156), 2,4,4,6-3,5-dibenzoyltetrahydropyran (155,156), o-nitrobenzylidenedesoxybenzoin (157), p-nitrobenzylidene-desoxybenzoin (157), N-(3-pyridyl)sydnone (158,159), tetrabenzoyl-ethylene (160), and the oxidation product of 2,4,5-triphenylimidazole (161,162). 

Inhibition Studies. A number of compounds were employed to study the amino acid residue(s) that are important for cellulase activity. Samples of enzyme (0.1 mL, 500 units) were pre-incubated with 0.1 mL of inhibitor in semimicroviscometers for 8 min at 35°C. CM-cellulose solution (0.8%, w/v), which had been separately equilibrated at 35°C for 20 min was added to the viscometers and initial viscosity losses were measured after 15 min. Inhibitors were replaced by buffer in control experiments. Compounds that are insoluble in buffer, e.g., N-ethylmalei-mide, diisopropyl fluorophosphate, and succinic anhydride, were dissolved in a small volume of 95% ethanol before assay. p-Chloromercuribenzoate (p-CMB) was first dissolved in 0.2M NaOH and the pH adjusted to eight prior to pre-incubation with cellulases. 

A racemic alcohol is resolved in the form of a monoester derived from phthalic anhydride of succinic anhydride. Thus, the diastereomeric salt of the monoester with a resolving amine is purified by crystallization. Also, optically active monoesters are recovered from the salts, and hydrolysed to give optically active alcohols (Fig. 10).23... 

An extensive study, summarized in Table VII, was carried out which established the effect of hydrochloric acid-succinic anhydride as combined activators on properties of boards made using maleic anhydride as the crosslinking agent. Data in Table VII is presented in two parts. In Fart A experiments are summarized in which either one or two of the three additives tab re used in the formulations in Part B all three additives were used. 

Effects of Hydrochloric Acid and Succinic. Peroxide Activators and Maleic Anhydride on Particle board3. Properties Part A Results Using Either 1 or 2 Formulating Agents... 

To complete the total synthesis of the optically active form of veatchine, the successful resolution of the synthetic racemic ketone 244 was accomplished. Compound 244 was reduced stereoselectively with sodium boro-hydride to give the alcohol 248. The latter was heated with succinic anhydride and pyridine in xylene to yield the racemic half-ester 249. Treatment of 249 with brucine afforded the diastereoisomeric brucine salts, which were separated by fractional crystallization. The separated salts were decomposed... 

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