The polycondensation of tetrahydrofuran with maleic anhydride catalyzed by Maghnite-H+ (Mag-H) was investigated. Maghnite is a montmorillonite sheet silicate clay that is exchanged with protons to produce Maghnite-H [1]. It was found that the polymerization in bulk is initiated by Mag-H in the presence of acetic anhydride at 40 degrees C. The effects of the amounts of Mag-H and acetic anhydride...

Naphthalic anhydride is a seed-applied herbicide safener which reduces the toxicity of ima­ zethapyr, an imidazolinone herbicide, to maize (Zea mays L.). Protection of maize from ima­ zethapyr was dependent on the amount of naphthalic anhydride applied to the seed. M etabo­ lism of imazethapyr by maize roots and shoots was increased by exposure of the roots to a solution containing naphthalic a...

Acetylation with acetic anhydride, under both aqueous and anhydrous conditions, has been utilized to derivatize various biogenic amines and psychotropic drugs for subsequent analysis by gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS). Under basic aqueous conditions, acetic anhydride derivatizes phenols and amines but not alcohols; under anhydrous conditions, all three fu...

The esterification reaction of trimellitic anhydride chloride TMAC 1 with N-(hydroxymethyl) phthalimide NHMP 2, N-(2-hydroxyethyl) phthalimide NHEP 3 or N-(hydroxymethyl) thalidomide NHMT 4 afforded novel cyclic imide-ester derivatives; phthaloyl-phthalic anhydride methyl ester PPAME 5, phthaloyl-phthalic anhydride ethyl ester PPAEE 6 and thalidomide-phthalic anhydride methyl ester TPAME 7, res...

The filamentous fungus Byssochlamys fulva strain IMI 40021 produces (+)-byssochlamic acid 1, its novel dihydroanalogue 2 and four related secondary metabolites. Agnestadrides A, 17 and B, 18 constitute a novel class of seven-membered ring, maleic anhydride-containing (hence termed heptadride) natural products. The putative maleic anhydride precursor 5 for both nonadride and heptadride biosynthe...

BACKGROUND Enzymes show relative instability in solvents or at elevated temperature and lower activity in organic solvent than in water. These limit the industrial applications of enzymes. RESULTS In order to improve the activity and stability of chloroperoxidase, chloroperoxidase was modified by citraconic anhydride, maleic anhydride or phthalic anhydride. The catalytic activities, thermosta...

Phthalic, maleic and succinic anhydrides have been reacted with aromatic amines to obtain the corresponding monoacid monoamides. The latter have been each transformed into the corresponding cyclic imide derivatives by treating with SOCl2. Alternatively, anhydrides have been reacted with methanolic KOH to obtain monomethyl ester derivatives which on reaction with aromatic amines in the presence ...

Anhydride copolymers were synthesized from acrylic acid and fatty alcohols (C12- C18, C18:1). These n-alkyl acrylates were treated with maleic anhydride in presence of hydrogen peroxide in second step, to form anhydride copolymer. The anhydride copolymer further reacted to n-butylamine to form poly (n-acrylate-co-nbutylmalemide). The compounds were used as pour point depressant (PPD) additive. ...

Bagasse acetate butyrates were prepared homogeneously in 1-butyl-3methylimidazolium chloride ([C4mim]Cl) ionic liquid from ball-milled sugarcane bagasse by acylation with acetic anhydride and butyric anhydride. The parameters, including reaction temperature, reaction time, feeding method of adding anhydrides, the dosage of total anhydrides to SCB, and the molar ratio of acetic anhydride to buty...

We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carbo...