• Journal of the Korean Chemical Society
• /
• v.48 no.6
• /
• pp.609-615
• /
• 2004

Alkoxyallylthiopyridazine derivatives which exhibit superior effect for the treatment of hepatic diseases were synthesized from maleic anhydrides. The reaction of maleic anhydrides with hydrazine monohydrate in aq HCl at reflux afforded dihydroxypyridazines, which were transformed to dichloropyridazines with phosphorus oxychloride. The substitution of the first chlorine atom in dichloropyridazines proceeded selectively with alcoholic sodium alkoxides in THF to afford alkoxychloropyridazines, which were converted to alkoxyallylthiopyridazines with lithium 2-propene-1-thiolate in high yields.

• Journal of Photoscience
• /
• v.10 no.3
• /
• pp.241-243
• /
• 2003

Photoreactions of some carbonyl compounds with TiO$_2$ were investigated in methanol. Although 1,3-cyclohexanedione and phthalimide afforded 3-methoxy-2-cyclohexen-l-one and 3-methoxy-1-isoindolinone, respectively, acid anhydrides such as succinic, phthalic, and maleic anhydrides gave the monoesters of dicarboxylic acids in good to excellent yields, when they were irradiated on TiO$_2$ in methanol with 300 nm UV light.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.1
• /
• pp.83-91
• /
• 2009

To develop new anticancer agents, 3-allylthio-6-aminopyridazine derivatives were synthesized from maleic anhydrides or phthalic anhydrides by formation of a pyridazine nucleus, dichlorination, allylthiolation and amination. The pyridazine nuclei were obtained by condensing a hydrazine monohydrate with maleic anhydride. An allylthio group as a pharmacologically active group was introduced into one side of a pyridazine ring. Arylalkylamines with benzene or pyridine moieties or heterocycloalkylamines with heterocycle moieties such as morpholine, piperidine, or pyrrolidine were also introduced into the para-position of allylthio pyridazine. These new compounds showed antiproliferative activities against SK-Hep-1 human liver cancer cells in MTT assays. These compounds are thus promising candidates for chemotherapy of hepatocellular carcinomas. Two compounds, 20c and 22a, showed higher potencies for inhibiting growth of hepatocellular carcinoma cells than did K6 ($ID_50$=1.08 mM). This suggests the potential anticancer activity of these two compounds.

• Applied Chemistry for Engineering
• /
• v.3 no.1
• /
• pp.179-187
• /
• 1992

Poly(styrene-co-maliec anhydride) was reacted with aromatic amines such as aniline, p-toluidine, and p-chloroaniline in 10% (w/w) DMF solution to convert maleic anhydride units into maleimides. Optimum reaction conditions for cyclodehydration step of imide ring formation were : (a) reaction temp. of $80^{\circ}C$ (b) mole ratios of cyclodehydration agents : anhydride units in SMA/acetic anhydride/sodium acetate/triethyl amine= 1.0/2.0/0.2/1.1. $T_g$of SMI(imide modified SMA) was increased with increasing degree of imidization, but $T_g$leveled off in the early stage of imide content. And $T_g$of SMI was increased with the following order of amines used for imidization reagents : aniline < p-toluidine < p-chloroaniline.

• Archives of Pharmacal Research
• /
• v.28 no.3
• /
• pp.364-369
• /
• 2005

HPMC (Hydroxypropyl methylcellulose) was chemically modified, using maleic anhydrides, to obtain pH-sensitive HPMCAM (Hydroxypropyl methylcellulose acetate maleate) polymers for use as novel duodenum-specific coating agents. The pharmaceutical properties of HPMCAM, such as film forming, acid values, pH-sensitive values, water vapor permeability, tensile strength and Tg, were investigated, and found to show good film forming properties. The pH­sensitive values were 3.0 to 3.7. In vitro results demonstrate that HPMCAM could completely suppress drug release within 2h in a simulated gastric fluid (pH 1.2) and rapidly release the drug in a simulated pathological duodenal fluid (pH 3.4). These results indicate that HPMCAM might be a useful material for a duodenum-specific drug delivery system.

• Applied Chemistry for Engineering
• /
• v.7 no.5
• /
• pp.888-901
• /
• 1996

Oxidations of cyclopentene and of 1-pentene with air have been studied on a V/Mo/P/Al/Ti-mixed oxide catalyst in a fixed bed integral reactor. At high levels of conversion maleic anhydride was in each case produced as the major organic product, along with minor amounts of phthalic anhydride and, only starting from 1-pentene, also of citraconic anhydride. At lower levels of conversion a total of 30 organic products have been identified, some of which may be intermediates on the way from the substrates to the three anhydrides mentioned above. Based on the dependence of selectivities of the organic products on conversion, reaction schemes for the formation of maleic anhydride, phthalic anhydride and citraconic anhydride have been proposed. Oxidation at $310^{\circ}C$ led to increasing conversions and selectivities for maleic anhydride with decreasing space velocities. The highest selectivities for maleic anhydride were obtained at conversion of ca. 100%. Oxidation at a constant space velocity of $2{\cdot}10^4h^{-1}$ led to increasing conversions with increasing temperatures in the range of $300^{\circ}C{\sim}420^{\circ}C$, while the selectivity for maleic anhydride passed through a maximum value of ca. 39% at $370^{\circ}C$ in the oxidation of cyclopentene and a maximum value of ca. 30% at $400^{\circ}C$ in the oxidation of 1-pentene.