Synthesis and reactions of 4H-3,1-benzoxazin-4-one derivative bearing pyrazolyl moiety as antimicrobial and antioxidant agents

Ring opening of 4-aryl-2-phenyloxazol-5-one 1 with 2-aminobenzoic acid in acetic acid and n-butanol gave compounds 2 and 3, respectively. The 4H-3,1-benzoxazin-4-one derivative 4 was synthesized by refluxing of compound 2 in acetic anhydride. Then it reacted with different nitrogen nucleophiles such as hydrazine hydrate, phenylhydrazine, cyclohexylamine, piperidine, ethylenediamine, ethanolamine, semicarbazide hydrochloride, cyanoacetohydrazide and methyl glycinate hydrochloride to give compounds 5–14 in order to study the behavior of these nucleophilic reagents on the performed ring system. All the structures of the newly prepared compounds were characterized by their IR, ¹H-, 13C-NMR and MS spectral data. Some of the synthesized compounds were screened for their antimicrobial and antioxidant activities. Compound 5 showed remarkable activity upon this screening.     

Metal-Free Twofold Electrochemical C−H Amination of Activated Arenes: Application to Medicinally Relevant Precursor Synthesis

The efficient production of many medicinally or synthetically important starting materials suffers from wasteful or toxic precursors for the synthesis. In particular, the aromatic non-protected primary amine function represents a versatile synthetic precursor, but its synthesis typically requires toxic oxidizing agents and transition metal catalysts. The twofold electrochemical amination of activated benzene derivatives via Zincke intermediates provides an alternative sustainable strategy for the formation of new C−N bonds of high synthetic value. As a proof of concept, we use our approach to generate a benzoxazinone scaffold that gained attention as a starting structure against castrate-resistant prostate cancer. Further improvement of the structure led to significantly increased cancer cell line toxicity. Thus, exploiting environmentally benign electrooxidation, we present a new versatile and powerful method based on direct C−H activation that is applicable for example the production of medicinally relevant compounds.     

Novel method for preparation of poly(benzoxazinone‐imide)

A novel method was developed to prepare poly(benzoxazinone‐imide) by the dealcoholization of poly(amide‐imide), having pendent ethoxycarbonyl groups, which was prepared from poly(amide acid). The poly(amide acid) was prepared from the reaction of pyromellitic dianhydride and 4,4′‐diamino‐6‐ethoxycarbonyl benzanilide. The curing behavior of the poly(amide acid) was monitored by DSC, which indicated the presence of two broad endotherms, one with maximum at 153 °C due to imide‐ring formation and the other with maximum at 359 °C due to benzoxazinone‐ring formation. The poly(amide acid) was thermally treated at 300 °C/1 h to get poly(amide‐imide) with pendent ester groups, then at 350 °C/2 h to convert into poly(benzoxazinone‐imide) by dealcoholization. Viscoelastic measurements of the poly(amide‐imide) showed that the storage modulus dropped at about 280 °C with glass‐transition temperature (T_g ) at about 340 °C. The storage modulus of poly(benzoxazinone‐imide), however, was almost constant up to 400 °C and no T_g was detected below 400 °C. Also, the tensile modulus and tensile strength of the poly(benzoxazinone‐imide) was much higher than that of the poly(amide‐imide). The 5% decomposition of poly(benzoxazinone‐imide) film was at 535 °C, which reflects its excellent thermal stability. Also, poly(benzoxazinone‐imide) showed more hydrolytic stability against alkali in comparison to polyimides. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1647–1655, 2000     

2-取代的6-溴甲基-4(3H)-喹唑啉酮的合成

2-取代的6-溴甲基-4(3H)-喹唑啉酮的合成;4(3H)-喹唑啉酮;苯并噁嗪酮;N-溴代琥珀酰亚胺; 合成     

Pd-Catalyzed Carbonylative Synthesis of 4H-Benzo[d][1,3]Oxazin-4-Ones Using Benzene-1,3,5-Triyl Triformate as the CO Source

A facile synthesis of 4H-benzo[d][1,3]oxazin-4-one derivatives by Pd-catalyzed carbonylative cross-coupling between N-(ortho-bromoaryl)amides and benzene-1,3,5-triyl triformate (TFBen) was developed. This procedure does not require the toxic and flammable gas CO as the carbonyl source and tolerates a wide scope of functional groups. Remarkably, 4H-benzo[d][1,3]oxazin-4-ones incorporated to natural products and drugs can be constructed by this method.     

Ecofriendly and highly efficient microwave-induced synthesis of novel quinazolinone-undecyl hybrids with in vitro antitumor activity

Abstract

Novel N-alkyl-quinazolin-4-one derivatives 3–5 were obtained from reaction of 6-Iodo-2-undecylquinazolin-4(3H)-one (2) with different alkyl halides. Hydrazinolysis of compound 5 gave the acetohydrazide 6 which reacted with different carbon electrophiles to produce 2-undecyl-4(3H)-quinazolinone derivatives. The new products were obtained by either conventional method or by microwave assisting technique and the structure of all products was confirmed by elemental and spectral data. The ecofriendly microwave provides an efficiency over than conventional method in many aspects. All the synthesized products were tested in vitro against a panel of three human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, colon cancer HCT-116, and mammary gland breast MCF-7. Almost all of the tested compounds showed satisfactory activity.     

Regioselectivity and regiospecificity of benzoxazinone (2-isopropyl-4H-3,1-benzoxazinone) derivatives toward nitrogen nucleophiles and evaluation of antimicrobial activity

A novel group of 6-iodoquinazolin-4(3H)-one derivatives was prepared. The reaction of the benzoxazinone 3 with various nitrogen nucleophiles such as formamide and hydrazine hydrate and also the reaction of the isopropylquinazolinone 4 with hydrazonyl chloride have been shown to proceed with a high degree of regioselectivity at C(2). Spiro heterocycles have been found to play fundamental roles in biological processes and have exhibited diversified biological activity and pharmacological and therapeutical properties; thus reaction of acetohydrazides 10a–c afforded the spiro compounds 11a–c. The acetohydrazide derivative 7 reacted with carbon electrophiles such as acetylacetone, ethyl acetoacetate, acid chlorides, and benzaldehyde to give some interesting heterocyclic compounds 12–16, respectively. The structures of all the synthesized compounds were inferred by infrared, ¹H NMR, and mass spectra as well as elemental analyses. The antimicrobial activities of some of the synthesized products were preliminarily evaluated.