5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物的高效合成

在分子碘作用下,以吲哚、醛和2,2-二甲基-1,3-二噁烷-4,6-二酮为原料,通过三组分缩合反应合成了10种5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物。 当催化剂的用量为5%(摩尔分数)时,30 ℃反应60~90 min,收率为71.4%~97.3%。 此外,还探讨了分子碘的催化机理。     

Synthesis of 1,6-disubstituted 2,4-pyridinediones from 5-acetoacetyl-2,2-dimethyl-1,3-dioxane-4,6-dione

5-Acetoacetyl-2,2-dimethyl-1,3-dioxane-4,6-dione reacts with aliphatic amines and p-methoxy-aniline to afford the corresponding 5-[3-alkyl(or aryl)amino-2-butenoyl] derivatives. Heating of the latter in boiling toluene gives 86–90% of N-substituted 6-methylpyridine-3-carboxylic acids which undergo decarboxylation in diethylene glycol dimethyl ether at 160°C, leading to N-substituted 6-methyl-1,2,3,4-tetrahydro-pyridine-2,4-diones in high yields.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1376–1378.Original Russian Text Copyright © 2004 by Rubinov, Zheldakova, Rubinova.     

磷酸二氢钾催化Yonemitsu缩合反应合成5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物

以醛、吲哚和麦氏酸为原料,水和乙醇混合液为溶剂,在室温搅拌条件下以磷酸二氢钾为催化剂通过Yonemitsu缩合反应,合成了一系列的5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物,产率为48%~98%,并通过X射线单晶衍射仪测定了化合物4o的晶体结构。 该方法能够有效的促使反应活性较低的4-甲基苯甲醛和4-甲氧基苯甲醛参与反应,以83%和60%的收率获得相应的目标产物,并具有反应条件温和、催化剂廉价易得、后处理简单、产物易于纯化、产率较高等优点,可用于合成3-取代吲哚类化合物。     

2,2-Dimethyl-5-(5-r-2-furfurylidene)-1,3-dioxane-4,6-diones

2,2-Dimethyl-5-(5-methyl-2-furfurylidene)-1,3-dioxane-4,6-dione crystals were subjected to an x-ray diffraction study. The unit cell of the crystal contains two symmetrically independent A and B molecules that exist in the x-cis conformation, which is stabilized by conjugation between the heteroring and, possibly, an intramolecular hydrogen bond.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1453–1456, November, 1988.     

无溶剂、无催化剂条件下5-[(3-吲哚基)-芳甲基]-2,2-二甲基- 1,3-二氧六环-4,6-二酮的合成

在无溶剂和催化剂条件下,由芳香醛、吲哚、丙二酸亚异丙酯的三组分缩合反应,制备了5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二氧六环-4,6-二酮,产率为70%～85%,产物结构经1H NMR,IR确证.     

Simple,Safe, Large Scale Synthesis of 5-Arylmethyl-2,2-dimethyl-1,3-dioxane-4,6-diones and 3-Arylpropanoic Acids

Reaction of aryl aldehydes with Meldrum's acid 2 in the presence of formic acid and triethylamine gives 5-arylmethyl Meldrum's acid derivatives 4 at room temperature, whereas at 80–100°C 3-arylpropanoic acids 5 are formed.     

Preparative synthesis of 2,2-dimethyl-5-(trifluoroacetyl)-1,3-dioxane-4,6-dione (2-trifluoroacetyl Meldrum's acid) and 2,2-dimethyl-6-(trifluoromethyl)-4H-1,3-dioxin-4-one and their synthetic usefulness as (trifluoroacetyl)ketene precursors

A simple and reliable method for the preparation of 2,2-dimethyl-5-(trifluoroacetyl)-1,3-dioxane-4,6-dione and 2,2-dimethyl-6-(trifluoromethyl)-4H-1,3-dioxin-4-one on a multigram scale was developed. These (trifluoroacetyl)ketene precursors were used in the hetero-Diels-Alder reaction with dialkylcyanamides and 1-ethoxyprop-1-yne, as well as in some reactions with nucleophiles.     

2,2-dimethyl-5-(5-r-furfurylidene)-1,3-dioxane4,6 diones 7. Synthesis,structure, and properties of 2,2dimethyl-5-(3-furfuryldiene and 3-thienylidene)-1,3dioxane-4,6-diones

The corresponding 3 furfurylidene(thienylidene)-dioxanediones were obtained by the reaction of 2,5-R,Rfuran(thiophen)-3-carbaldehydes with Meldrum's acid. It was shown by x-ray crystallographic analysis that they have the s-trans disposition at the C₍₂₎=C₍₃₎ bond of the five-membered heterocycle and an exocyclic multiple bond. The character of the conjunction in their molecules was considered in the light of data of x-ray crystallographic analysis, electronic spectra, and NMR. The corresponding 3-furfuryl(thienyl)]dioxanediones were obtained by the selective ionic hydrogenation of the exocyclic double bond.For part 6 see [1]Kuban State Technological University, Krasnodar 350072. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 899–905, July, 1995. Original article submitted October 25, 1994; revision submitted June 5, 1995.     

Synthesis of 2-substituted 5-(1,3-dithiolan-2-ylidene)-1,3-dioxane-4,6-dione derivatives

Some 2-substituted 5-(1,3-dithiolan-2-ylidene)-1,3-dioxane-4,6-dione derivatives 3 were prepared from the condensation reaction of 1,3-dithiolan-2-ylidenemalonic acid ( 2 ) with carbonyl compounds in 40–93% yields.     

5-[5-R-furfurylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones 5. Nucleophilic replacement of halogen in the furan ring

Halogen in positions 3 and 5 of the furan ring in ftirfurylidenedioxanediones is readily replaced by dithiocarbonate, dithiocarbatnate, dithiophosphate, thiocyanate, and azide anions, and by thiourea, and secondary and tertiary amines. The conformation of the initial halogen derivative is retained in the substitution products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 327–334, March, 1994.     

5-[5-R-furfurylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones 6. Synthesis,structure, and properties of substituted furylimino- and furfurylidenephosphoranes. Molecular and crystal structure of N-[5-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)methyl-2-furylimino(triphenyl)phosphorane

Furylimino- and furfurylidenephosphoranes have been synthesized by sequential conversions of 5-unsubstituted and 5-methylfurfut),Iidetiedio.yanediones. The ylide fragment linked directly with the furfurylidenedioxanedione residue displays strong electron-donating properties, as a result of which resonance occurs in the system of conjugated bonds. The molecular and crystal structure of the iminophosphorane was studied by x-ray structural analysis and the resonance of the bonds in the molecule was confirmed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 335–344, March, 1994.     

Reactions of methoxybenzylidene derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione and their saturated analogs with certain nucleophilic reagents

The reactions of the methoxybenzylidene derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione and their saturated analogs with potassium hydroxide in methanol, ammonia, and hydrazine hydrate were realized. The 1,2-bis(methoxybenzylidene)hydrazines, amides, and hydrazides of methoxybenzylidene-malonic acid, suitable for use as structural blocks in the synthesis of various structures based on them, were prepared and characterized.     

New thiourea organocatalysts and their application for the synthesis of 5-(1H-indol-3-yl)methyl-2,2-dimethyl-1,3-dioxane-4,6-diones a source of chiral 3-indoylmethyl ketenes

The stereoselective properties of modified thiourea organocatalysts were tested in the Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones, which produces chiral 5-((1H-indol-3-yl)(aryl)methyl)-2,2-dimethyl-1,3-dioxane-4,6-diones. Based on a tentative reaction mechanism for ((S)-N-benzyl-2-(3-(3,5-bis(trifluoromethyl)phenyl)thioureido)-N,3,3-trimethylbutanamide organocatalysts, modifications were applied in four selected regions. Systematic structure-stereoselectivity relationship study allowed designing the best efficient organocatalyst for the investigated Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones.     

Discovery and preliminary SAR of 5-arylidene-2,2-dimethyl-1,3-dioxane- 4,6-diones as platelet aggregation inhibitors

We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone.