Synthesis of 5-phenyl-2,3,8,9-tetramethoxy-11H-indeno[1,2-c]isoquinoline

A novel approach to the title compound 10 starting with a conveniently available cinnamic acid is proposed. It involves a Friedel-Crafts reaction followed by the synthesis of the amide and subsequent cyclodehydration via a Bischler-Napieralski reaction.     

Synthesis of substituted [1,2,4]oxadiazino[2,3-a]indole-7,8-dicarbonitriles

1. Download high-res image (81KB)
2. Download full-size image

     

7,8-二氢-6,6-二甲基-7,8-环氧-6氢-吡喃[2,3-f]苯并-2,1,3-恶二唑的合成

本文给出了一条较好的制备7,8-二氢-6,6-二甲基-7,8-环氧-6氢-吡喃[2,3-f]苯并-2,1,3-恶二唑的合成路线，即由对乙酰氨基苯酚经酯化、Fries重排、环合、还原、脱水、硝化、脱酰基、氧化、脱氧和催化环氧化等反应制得标题化合物，其结构经元素分析和光谱数据确证。     

A novel synthesis of pyrido[2,3-α]indolizine

The synthesis of a new pyridoindolizine, in particular, pyrido[2,3-α]indolizine, was carried out using 2-methyl-3-t-butoxycarbonyl-4-aminopyrrole as the starting material.     

Convenient and Efficient Synthesis of 11‐Amino‐2,8‐substituted‐2,3,8,9‐tetrahydrobenzo[4,5]thieno[2,3‐b]quinolinone Derivatives

The Gewald reactions of 5‐substituted‐1,3‐cyclohexanedione, malononitrile, and powdered sulfur were carried out to give the corresponding products 2‐amino‐5‐substituted‐7‐oxo‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carbonitrile derivatives 1 . The intermediate enamines 2 were prepared by reaction of compounds 1 and 5‐substituted‐1,3‐cyclohexanedione with hydrochloric acid as catalyst. The title compounds 11‐amino‐2,8‐substituted‐2,3,8,9‐tetrahydrobenzo[4,5]thieno[2,3‐b]quinolinone 3 were synthesized by cyclization of compounds 2 in the presence of K₂CO₃ and Cu₂Cl₂. The structures of all compounds were characterized by elemental analysis, IR, MS, and ¹H‐NMR spectra.     

Synthesis and Crystal Structure of 7,8-Dihydroquinolino[2,3-a]acridine Derivatives

Novel 9-amino-3-substituted-1,2,3,4-acridin-1-one derivatives and 9,14-diamino-7-substituted-7,8-dihydroquinolino[2,3-a]acridine derivatives were synthesized by the condensation reaction of 5-substituted-1,3-cyclohexanedione with 2-aminobenzonitrile and substituted 2-aminobenzonitrile using p-toluenesulfonic acid, K₂CO₃, and Cu₂Cl₂ as catalysts. The structures of all compounds were characterized by elemental analysis, infrared, mass spectrometry, and ¹H and ¹³C NMR spectra. The crystal and molecular structures of 6, 14-diamino-3,4,11,12-tetramethoxy-7-phenyl-7,8-dihydroquinolino[2,3-a]acridine 5a have been determined by single-crystal x-ray diffraction analysis. The crystal of compound 5a belongs to triclinic with space group P-1, a = 1.06168(15) nm, b = 1.16951(17) nm, c = 1.6020(2) nm, α = 71.380(3)°, β = 77.686(3)°, γ = 66.743(3)°, Z = 2, V = 1.7231(4) nm³, R ₁ = 0.1060, and wR ₂ = 0.2192.     

Synthesis of 2,6-disubstituted-7,8-dihydro-6H-pyrano[2,3-6]pyrazines

A straightforward synthesis of a 2,6-disubstituted-7,8-dihydro-6H-pyrano[2,3-6]pyrazine is described. The synthesis relies on a versatile dichloropyrazine–aldehyde intermediate and an olefination partner.     

Synthesis of 5,6-dihydro-4H-pyrrolo[1,2-a]thieno[2,3-f][1,4]diazepines

The reduction of 1-[3-(thienyl-2-carbonitrile)]pyrrole, formed by condensation of 3-aminothiophene-2-carbonitrile with 2,5-dimethoxytetrahydrofuran, gave 1-[3-(thienyl-2-aminomethyl)]pyrrole. This compound was found to be a convenient intermediate for the preparation of 4-aryl-5,6-dihydro-4H-pyrrolo[1,2-a]thieno-[2,3-f][1,4]diazepines which was accomplished by two different synthetic routes.     

Synthesis of 3-substituted-4-phenyl-2-thioxo-1,2,3,4,5,6,7,8-octahydrobenzo[4,5]thieno[2,3-á]pyrimidines

The reactions between 3-benzoyl-2-isothiocyanato-4,5,6,7-tetrahydrobenzo[b]thiophene and hydrazine or primary amines have been studied. The products obtained were identified as derivatives of 4-phenyl-2-thioxo-2,3,5,6,7,8-hexahydrobenzo[4,5]thieno[2,3-d]pyrimidine. Their easy reduction with sodium borohydride provided a useful method for the synthesis of 3-substituted-4-phenyl-2-thioxo-1,2,3,4,5,6,7,8-octahydrobenzo[4,5]thieno[2,3-d]pyrimidines. Both kind of compounds were evaluated as potential analgesic, anti-inflammatory and anti-arthritic agents.