Special Issue

Edward C. Taylor's Special Issues, Vol. 35, No. 2, 1993

97 data found. 61 - 90 listedFirst Previous Next Last
Paper | Special issue | Vol 35, No. 2, 1993, pp.1005-1014
Published online:
DOI: 10.3987/COM-92-S(T)95
Formation and Reaction of p-Quinol Acetates of N-Trifluoroacetyltetrahydroisoqunolin-7-ols

Osamu Hoshino,* Hiromichi Ogasawara, Minoru Arasawa, Masaji Suzuki, and Kazuaki Iizima

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 12, Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan

Abstract

Lead tetraacetate oxidation of N-trifluoroacetyltetrahydroisoquinolin-7-ols (13a, b) in AcOH gave stable p-quinol acetates (17a, b). Reaction of 17 with trifluoroacetic acid in CH2CI2 or MeCN gave morphinandienones (15) and aporphines (16), respectively. In contrast with o-quinol acetates (14), it was found that reaction of p-quinol acetates (17) in MeCN was considerably slower than that in CH2Cl2. A mechanistic pathway on the reaction is deduced.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1015-1027
Published online:
DOI: 10.3987/COM-92-S(T)96
Synthesis of Indole Glycosinolates, Sugar Variants of Naturally Occurring Glucobrassicin

Christian Gardart, Alain Quinsac, Benoît Joseph, and Patrick Rollin*

*Laboratoire de Chimie Bioorganique et Analytique, Université d'Orléans, BP 6759, Rue de Chartres, 45067 Orleans Cedex 2, France

Abstract

Eight sugar-variants (3c-10d) of naturally ocurring glucobrassicin (2c) were synthesized via nucleophilic addition of glycosyl mercaptans on a common nitrile-oxide intermediate.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1029-1037
Published online:
DOI: 10.3987/COM-92-S(T)97
Photo-oxidative Cleavage of a Furan-Azetidinone Carbon-Carbon Bond: A Synthesis of 4-Acetoxyazetidinone

Joseph E. Lynch,* William L. Laswell, Ralph P. Volante, Robert A. Reamer, David M. Tschaen, and Ichiro Shinkai

*Process Research, Merck Research Laboratories, Division of Merck & Co., Inc., P.O.Box 2000 Rahway, NJ 07065, U.S.A.

Abstract

A stereoselective synthesis of the 4-acetoxyazetidinione (1) from methyl 3(R)-hydroxybutyrate is reported. The synthesis involved stereoselective preparation of a 4-(2-furanyl)azetidinone that was allowed to react with singlet oxygen. The resulting endoperoxide intermediates underwent direct rearrangement to an acyloxyazetidinone that on reaction with sodium acetate gave 1 in modest yield. An improved yield of 1 was obtained by treatment of the endoperoxides with hydrogen peroxide followed by acetic anhydride to give an α-alkoxy acylperoxide that underwent thermal rearrangement to 1.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1039-1053
Published online:
DOI: 10.3987/COM-92-S(T)98
BF3ÅEOEt2 Catalyzed [4+2] Cycloaddition Reactions of N-Aryl Schiff's Bases with 1-Alkenyl, 1,2-Propadienyl, and 1-Alkynyl Sulfides

Koichi Narasaka* and Takanori Shibata

*Department of Chemistry, Faculty of Science,University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033

Abstract

[4+2] Cycloaddition reaction proceeds between N-aryl Schiff’s bases and 1-alkenyl sulfides, a 1,2-propadienyl sulfide, or 1-alkynyl sulfides in the presence of BFOEt2 to provide 2-substituted quinoline derivatives. A 2-alkyl-4-quinolone alkaloid, leptomerine, is prepared by applying the present cycloaddition reaction.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1055-1066
Published online:
DOI: 10.3987/COM-92-S(T)102
Pyrimido[4,5-d]pyrimidines, Pyrimido[4',5':4,5]pyrimido[6,1-a]azepines, and an Imidazo[5,1-f][1,2,4]triazine by Three Component Reaction

Heinrich Wamhoff* and Andreas Schmidt

*Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, D-5300 Bonn 1, Germany

Abstract

Recent examples of the three component reaction: iminophosphoranes / isocyanates / heteroarenes (imines) are described. The uracil (1) affords with O-methyl-ε-caprolactim ether and isocyanates the pyrimido[4’,5’:4,5]pyrimido[6,1-a]azepines (6a-c) and with benzylideneaniline (8) the pyrimido[4,5-d]pyrimidines (9a-d), while azodicarboxylate gives the isofervenuline, pyrimido[4,5-e][1,2,4]triazine (11). Furthermore, pyrimido[4,5-d]pyrimidine (15) is obtained via 14 from 1, N-phenylbenzimidoyl chloride (13), and phenylisocyanate, while the tautomeric mixture 17A17B results from treatment of 6-aminouracil (16) with 13; interception with dimethyl acetylenedicarboxylate gives the pyrido[2,3-d]pyrimidine (19).

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1067-1074
Published online:
DOI: 10.3987/COM-92-S(T)104
Synthesis and Resolution of Bis- and Tris-(benzimidazol-1-yl)methanes

Vladimir Bobosík,* Concepción López, Rosa María Claramunt, Chiristian Roussel, Jean Louis Stein, Dominique Thiery, and José Elguero

*Departamento de Química Orgánica y Biología, Faclutade de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain

Abstract

Bis- and tris-(benzimidazol-1-yl)methane derivatives are reported with different substituents at position 2 of the benzimidazole ring. When the substituents are large enough, these compounds, even the bis-derivatives, can be resolved using hplc on CHIRALPAK OT(+) columns. For some compounds, the racemization barriers have been measured and their steric origin ascertained (δG‡ = a + b MR, MR being the molar refractivity).

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1075-1088
Published online:
DOI: 10.3987/COM-92-S(T)107
Stereochemical Observations in the Synthesis of Novel 1,4,5,9b-Tetrahydro-5-phenyl-2H-azeto[2,1-a]isoquinolin-2-one Derivatives

Samuel O. Nortey, David F. McComsey, and Bruce E. Maryanoff*

*Madical Chemistry Department, R. W. Johnson Pharmaceutical Research Institute, Spring House, Pennsylvania 19477, U.S.A.

Abstract

Imine (5) reacted with Cl2CHC(O)CI in the presence of Et3N to give β-lactams (7a) and (7b) in a 4:1 ratio. The stereochemistry of cycloadduct (7a) was confirmed by X-ray analysis. Uncyclized intermediates were identified. Reduction of dichloro β-lactam (7a) with Zn/HOAc gave mostly exo monochloride (13a), with high stereoselectivity (10:1 ratio). Reduction of a mixture of exo and endo monochlorides (13a) and (13b) with Zn/HOAc indicated that the more sterically hindered endo chlorine is preferentially attacked. Reduction of (7a) with Bu3SnH gave β-lactam (14a) as the major product.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1089-1101
Published online:
DOI: 10.3987/COM-92-S(T)109
Cycloaddition Reactions with Azabenzenes, XVIII. Synthesis of [2]Pyrindines

Hans Neunhoeffer,* Bernd Philipp, Brigit Schildhauer, Ralf Eckrich, and Uwe Krichbaum

*Institut für Organische Chemie, Technische Hochschule Darmstadt, Petersenstrasse. 22 D-6100 Darmstadt, Germany

Abstract

The reaction of 1,2,4-triazines (1) and 1-cyclopentenylpyrrolidine (2) afforded 6,7-dihydro-5H-[2]pyrindines (3) in good yields. Oxidation of 3 to the N-oxides (4), reaction of 4 with acetic anhydride to 5-acetoxy-6,7-dihydro-5H-[2]pyrindines (5) and elimination of acetic acid afforded [2]pyrindines (7). 2-Methyl-2H-[2]pyrindines (9) were also prepared.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1103-1120
Published online:
DOI: 10.3987/COM-92-S(T)110
A Convenient Synthesis of Pyrrole- and N-Aminopyrrole-3-propionate Esters

Peter A. Jacobi* and Guolin Cai

*Hall-Atwater Laboratories, Wesleyan University, Middletown, Connecicut 06459-0180, U.S.A.

Abstract

Trisubstituted pyrroles having a substitution pattern found in many naturally occurring linear and macrocyclic tetrapyrroles have been prepared in a regiospecific fashion by a two step sequence involving Diels-Alder reaction of 2-oxo-3-butenoate esters (58) with 2-alkoxy-1,3-pentadiene derivatives (46), followed by ozonolysis and Paal-Knorr cyclization.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1121-1123
Published online:
DOI: 10.3987/COM-92-S(T)111
An Improved Procedure for the Preparation of 2,2’-Spirobi[2H-1-benzopyran]

Muthiah Inbasekaran*

*Organic Chemicals and Polymers Laboratry, Central Research and Development, Building 1707, The Dow Chemical Company, Midland, Michigan 48674, U.S.A.

Abstract

A simple and improved procedure for preparing multi-gram quantities of 2,2’-spirobi[2H-1-benzopyran] (2) is reported. The cyclization of the dihydroxybenzopyran intermediate (1) into 2 proceeded smoothly when a solution of 1 in 2-ethoxyethyl acetate was heated under reflux for 3 hours.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1125-1140
Published online:
DOI: 10.3987/COM-92-S(T)112
The Reactions of o-Quinone Monoimides with Some Thiophenes and Furans

Harold W. Heine,* David K. Williams, Jennifer L. Rutherford, John Ramphal, and Elizabeth A. Williams

*Department of Chemistry, Bucknell University, Lewisburg, PA 17837, U.S.A.

Abstract

o-Quinone monoimides undergo inverse electron demand Diels-Alder reactions with thiophene, 2-alkylated thiophenes, 2- and 2,5-alkylated furans and benzofurans. 2,5-Dimethylthiophenes and 2-methylbenzo[b]thiophene, on the other hand interact with o-quinone monoimides to yield ethers, products arising from hydride abstractions from the methyl groups by the imido nitrogen of 6.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1141-1147
Published online:
DOI: 10.3987/COM-92-S(T)113
Application of the Intramolecular Schmidt Reaction to the Asymmetric Synthesis of (-)-Indolizidine 209B from Pulegone

Jeffery Aubé,* Pat S. Rafferty, and Gregory L. Milligan

*Department of Medicinal Chemistry, University of Kansas, 4070 Malott Hall, Lawrence, Kansas 66045-2506, U.S.A.

Abstract

A synthesis of enantiomerically pure indolizidine alkaloid 209B, beginning from naturally occurring pulegone, is described. The key step is the formation of a bicyclic lactam via the intramolecular Schmidt reaction of an alkyl azide with a cyclic ketone. The 11-pot synthesis was accomplished in an overall yield of 21.9%.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1149-1156
Published online:
DOI: 10.3987/COM-92-S(T)115
Squarylium Dyes Based on 2,6-Di-tert-butylselenopyrylium or Telluropyrylium Nuclei

Michael R. Detty* and Bruce Henne

*Office Imaging Research and Technology Development, Eastman Kodak Company, Rochester, New York 14650-2106, U.S.A.

Abstract

The condensation of 2,6-di-tert-butyl-4-methylselenopyrylium and -telluropyrylium salts with squaric acid gives squarylium dyes with absorption maxima at 847 and 910 nm, respectively, in dichloromethane. The condensation of a 2,6-di-tert-butyl-4-ethylselenopyrylium salt with squaric acid gives the corresponding dimethyl-substituted squarylium dye with an absorption maximum at 906 nm in dichloromethane. Electrochemical reduction and oxidation potentials of these dyes are compared to those of the corresponding squarylium dyes based on pyrylium and thiopyrylium nuclei.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1157-1170
Published online:
DOI: 10.3987/COM-92-S(T)117
Efficient Michael Addition Reactions of the N-Arylsulfonyl-3-phenylthiopiperidones. Synthesis of 3-Substituted Dihydropyrodinones

Masako Nakagawa,* Yasuhiro Torisawa, Toshihiro Hosaka, Kiyoshi Tanabe, Fabrice Tavet, Maki Aikawa, and Tohru Hino*

*Faculty of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

Efficient methods for the Michael addition reactions of N-arylsulfonyl-3-phenylthiopiperidones (1) with both the protected amidoacrylates (4,9) and the simple acrylates (12) have been developed. These reactions offer an efficient route to the 3-alkyl-substituted dihydropyridinones (3, 11), the dienophiles employed in the natural product synthesis.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1171-1184
Published online:
DOI: 10.3987/COM-92-S(T)118
One-Pot Synthesis of Pyrroles from N-Silyl-1-azaallyl Anions

Takeo Konakahara,* Atsuo Watanabe, Kazumi Maehara, Moriyo Nagata, and Marhaba Hojahmat

*Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Abstract

Some kinds of pyrroles, 1-pyrrolines, and 2H-pyrroles were synthesized from the N-silyl-1-azaallyl anions and α-diketones by an one-pot reaction.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1185-1203
Published online:
DOI: 10.3987/COM-92-S(T)119
Mild Preparation of 1-Benzyloxyiminoalkylphosphonic Dichlorides: Application to the Synthesis of Cyclic Phosphonic Diesters and Cyclic Monoester Amides

Richard Neidlein,* Holger Keller, and Roland Boese

*Pharmazeutisch Chemishes Institut, Im Neuenheimer Feld 364, 6900 Heidelberg, Germany

Abstract

1-Benzyloxyiminophosphonates (3) were converted under very mild conditions to the corresponding phosphonyl dichlorides (5). The application toward the synthesis of diastereomeric 1,3,2-oxazaphospholidines (6/7), and diastereomeric 1,3,2-dioxaphosphorinanes (8/9) is reported. The structure of 9a was confirmed by X-ray analysis.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1205-1235
Published online:
DOI: 10.3987/COM-92-S(T)120
Alkylation of Ambident Nucleophilic Hydroxamates with 4-Substituted 2-Azetidinones: Formation of Bicyclic β-Lactam Intermediates

Margaret J. Stauber, Thèrése Debiak-Krook, and Marvin J. Miller*

*Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A.

Abstract

Silver salts of various O-alkylhydroxamic acids react with 4-substituted 2-azetidinones (7) to produce novel substituted β-lactams. N- or O-alkylation of the hydroxamate silver salts can be controlled by reaction conditions, variation of the leaving group (OAc or SEt) of the 4-substituted 2-azetidinone, and the mode of formation of the silver salt itself. Elaboration of the products to azapenems and oxapenams may produce novel β-lactam derivatives for biological evaluation.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1237-1246
Published online:
DOI: 10.3987/COM-92-S(T)121
Structure of Adducts of 2-Arylaminothiazolines with Isocyanates and Isothiocyanates

Martin Avalos, Reyes Babiano, Pedro Cintas,* José L. Jiménez, Juan C. Palacios, and Concepción Valencia

*Departamento de Química Orgánica, Universidad de Extremadura, Avenida de Elvas s/n, 06071-Badajoz, Spain

Abstract

Extensions of the reaction of 2-chloroethyl isothiocyanate with aliphatic and aromatic amines have been accomplished, and 2-arylamino-2-thiazoline hydrochlorides (5) are easily obtained. Structures attributed initially to the products of condensation of 5 with phenyl isocyanate and phenyl isothiocyanate have been corrected and assigned unequivocally by X-ray analysis. By heating, these molecules do not undergo an endo-Nexo-N’ rearrangement.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1247-1258
Published online:
DOI: 10.3987/COM-92-S(T)123
2-Keto Sugars as Preformed Heterocyclic Building Blocks. Synthetic Studies

Andrew M. Griffin, Nicholas J. Newcombe, David Alker, Michael V. J. Ramsay, and Timothy Gallagher*

*School of Chemistry, University of Bristol, BS8 1TS, U.K.

Abstract

The synthesis of a series of bicyclic 2-hexulose derivatives (5), (6) and (7), which provide access to regiospecific carbohydrate-based ketone enolates, is described. The preparation of silyl enol ethers (21) and (22) from keto ether (5) and keto acetal (6), respectively, is also reported.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1259-1271
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DOI: 10.3987/COM-92-S(T)124
Prerparation of 1-Dimethyaminomethylene-3-alkenylindoles

Brian E. Love* and Prasad S. Raje

*Department of Chemistry, Auburn University, Extension Cottage-59 Duggar Drive Alabamaa 36849-5319, U.S.A.

Abstract

A one-pot synthesis of 1-dimethylaminomethylene-3-acylindoles is described, as well as their conversion to the corresponding 3-alkenylindoles.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1273-1278
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DOI: 10.3987/COM-92-S(T)125
Synthesis and Reaction of 1-Phenyl-4-trimethylstannyl-1,2,3-triazoles

Takao Sakamoto, Daishi Uchiyama, Yoshinori Kondo, and Hiroshi Yamanaka*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

1,3-Dipolar cycloaddition reaction of trimethylstannylacetylene with phenyl azide gave a regioselective product, 1-phenyl-4-trimethylstannyl-1,2,3-triazole. On the other hand, the reaction of trimethylstannyl-1-hexyne, -phenylacetylene, and -trimethylsilylacetylene with the azide yielded a mixture of the corresponding 4- and 5-trimethylstannyl-1-phenyl-1,2,3-triazoles. Detrimethylstannylation, iodination, benzoylation, and palladium-catalyzed phenylation of 4-trimethylstannyl- and 4,5-bis(trimethylstannyl)-1-phenyl-1,2,3-triazoles were also described.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1279-1287
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DOI: 10.3987/COM-92-S(T)126
Approach to the Synthesis of Astechrome

Hao Jing, Yutaka Aoyagi, and Akihiro Ohta*

*Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

The coupling reaction between 2-chloro-6-chloromethyl-5-methoxy-3-methylpyrazine 1-oxide and indolylmagnesium bromide gave 2-chloro-6-(indol-3-yl)methyl-5-methoxy-3-methylpyrazine 1-oxide, which was converted to a hydroxamic acid derivative via an indoline. The synthesis of 2-hydroxy-6-(indol-3-yl)methyl-5-methoxy-3-methylpyrazine 1-oxide, constituting the skeleton of astechrome, was accomplished from the Fe salt of the corresponding indolinehydroxamic acid derivative by oxidation with bis(salicylidene)ethylenediaminato cobalt(II) [Co(Salen)].

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1289-1307
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DOI: 10.3987/COM-92-S(T)128
Multisubstrate Analogue Inhibitors of Glycinamide Ribonucleotide Transformylase Based on 5-Deazaacyclo Tetrahudrofolate (5-DACTHF)

Eric C. Bigham,* W. Revill Mallory, Steven J. Hodson, David S. Duch, Robert Ferone, and Gary K. Smith

*Wellcome Research Laboratories, Burroughs Wellcome Co., 3030 Cornwallis Road, Research Triangle Park, NC 27709, U.S.A.

Abstract

N10-Substituted acetyl derivatives of 5-DACTHF are less active in general than the parent. However, multisubstrate analogue inhibitors that are 1000-fold more potent were synthesized, and N10-pyruvoyl-5-DACTHF serves as a precursor for a metabolically assembled multisubstrate analogue.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1309-1312
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DOI: 10.3987/COM-92-S(T)132
Synthesis of Fluorine Analogs of Hematoporphyrin

Akira Ando, Tamotsu Kitamura, Seiji Aono, Hidenobu Sato, Masaaki Omote, Mayumi Koyama, Toshiyuki Takagi, Takuichi Miki, Itsumaro Kumadaki,* and Haruo Sato

*Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata-shi, Osaka 573-0101, Japan

Abstract

With the aim of obtaining a porphyrin derivative useful for diagnosis and therapy of cancer, fluorine analogs of hematoporphyrin, which had trifluorohydroxyethyl group(s) in the place of hydroxyethyl groups, were synthesized by the reaction of deuteroporphyrin dimethyl ester with trifluoroacetaldehyde in the presence of aluminum chloride. Preliminary results of biological tests of the products showed that the hexafluoro analog of hematoporphyrin accumulates to Human liver cancer cells more selectively than other fluorine analogs.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1313-1329
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DOI: 10.3987/COM-92-S(T)133
Direct Amination of 3(2H)-Pyridazinones: Re-investigation of the Reaction of 3,6-Dimethoxypyridazine with Hydrazine

William J. Coates* and Alexander McKillop

*Medical Chemistry, SmithKline Beecham Pharmacuticals, The Frythe, Welwyn, Hertfordshire, AL6 9AR, U.K.

Abstract

3,6-Dimethoxypyridazine has been shown to react with hydrazine via 4-amination of 6-methoxy and 6-hydrazino-3(2H)-pyridazinones to give 4-amino-6-methoxy- and 4-amino-6-hydrazino-3(2H)-pyridazinones, and not the corresponding 5-amino isomers as previously reported. The published synthesis of the 5-amino isomers, used to confirm the earlier findings, is incorrect as regards 5-amino-6-hydrazino-3(2H)-pyridazinone, which has been prepared by an alternative route. The 4-amination reaction has also been extended to 6-chloro-3(2H)-pyridazinone.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1331-1339
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DOI: 10.3987/COM-93-S(T)135
Reaction of Methyl 2-Bensoylamino-3-dimethylaminopropenoate with Heterocycilc Hydroxy Compounds. The Synthesis of Fused Pyranoazines

Matej Kmetic, Branko Stanovnic,* Miha Tisler, and Thomas Kappe

*Department of Chemistry, University of Ljubljana, Murnikova 6, P. O. Box537, 61000 Ljubljana, Slovenia

Abstract

Methyl 2-benzoylamino-3-dimethylaminopropenoate (1) reacts in acetic acid with monocyclic or bicyclic heterocyclic compounds with two hydroxy or potential hydroxy groups in 1,3-position to give fused pyranones. Accordingly, derivatives of 2H-pyrano[3,2-c]pyridine (3), 2H-pyrano[3,2-c]quinoline (9,10, and 11), 2H-pyrano[2,3-d]pyridazine (13) , 8H-pyrano[3,2-d]tetrazolo[1,5-b]pyridazine (16) , pyrano[4,3-b]pyran (18) , and 2H-pyrano[2,3-c]pyridine (22) were obtained.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1341-1350
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DOI: 10.3987/COM-93-S(T)136
Components of the Bark of Artocarpus rigida BL.2. Structures of Four New Isoprenylated Flavone Derivatives Artonins M, N, O and P

Yoshio Hano, Ryohei Inami, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

Four new isoprenylated flavone derivatives, artonins M (1), N (2), O (3), and P (4), were isolated from the bark of Artocarpus rigida Bl., an Indonesian moraceous plant. The structures of artonins M, N, O, and P were determined to be formulae 1, 2, 3, and 4, respectively, on the basis of spectroscopic studies and chemical evidence.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1351-1369
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DOI: 10.3987/COM-93-S(T)139
Synthesis of an Orally Active PAF Antagonist of the N-[4-(3-Pyridinyl)butyl]pentqdienamide Class

Percy S. Manchand,* Alan Schwartz,* Steven Wolff,* Peter S. Belica, Pradeep Madan, Paresh Patel, and Sandra J. Saposnik

*Roche Research Center, Hoffman-La Roghe Inc., Nutley, New Jersey 07110, U.S.A.

Abstract

The PAF antagonist [R-(E,E)]-5-(4-methoxyphenyl)-N-[1-methyl-4-(3-pyridinyl)butyl]-2,4-decadienamide (2) was synthesized from (S)-α-methyl-3-pyridinebutanol (14), which was obtained either from ethyl lactate or by enantioselective kinetic hydrolysis of its racemate using the lipase derived from Pseudomonas cepacia (syn. P. fluorescens). Mesylation of 14, followed by azide displacement and hydrogenation, produced amine (7), which was coupled with the p-nitrophenol ester (8) to give 2. The direct coupling of (E,E)-5-(4-methoxyphenyl)-2,4-decadienoic acid (27) with azide (24) in the presence of tri-n-butylphosphine also gave 2. Acid (27) was prepared by a vinylogous Reformatsky reaction between ketone (25) and methyl 4-bromocrotonate.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1371-1395
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DOI: 10.3987/COM-93-S(T)143
Hydrogen Bond Directed Nitrile Oxide Cycloaddition Reactions of Allylic 2°-Amides

Dennis P. Curran,* Scott A. Gothe, and Sung-Mo Choi

*Department of Chemistry, University of Pittsburgh, Parkman Avenue & University Drive, Pittsburgh, PA 15260, U.S.A.

Abstract

The ability of allylic and homoallylic 2°-amides to direct nitrile oxide cycloaddition reactions has been studied. For N-cyclopentenyl amides, good regio- and stereochemical control are observed and mechanistic studies suggest that hydrogen bonding in the transition state selectively accelerates formation of one isomer. Acyclic allylic and homoallylic 2°-amides do not exhibit high regio- or stereoselectivity.

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Paper | Special issue | Vol 35, No. 2, 1993, pp.1397-1410
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DOI: 10.3987/COM-93-S(T)144
Fused Pyrimidines. Part 5. Pyrimido[4,5-d]pyrimidine Analogues of Folic Acid

Thomas. J. Delia,* Markus Baumann, and Amy Bunker

*Malcom H. Filson Laboratories, Department of Chemistry, Central Michigan University, Mt. Pleaasant, MI 48859, U.S.A.

Abstract

Pyrimido[4,5-d]pyrimidine analogues of folic acid have been prepared and tested for antitumor activity. Using Mannich reaction conditions, 2,4,6-triaminopyrimidine (12) or 2,4-diamino-6-oxopyrimidine (13) was treated with formaldehyde and either diethyl N-[4-(2-aminoethyl)benzoyl]-L-glutamate (18) or diethyl N-[4-(3-aminopropyl)benzoyl]-L-glutamate (24). The corresponding diester products (19, 20 and 25, 26) were converted to the diacids (5,6 and 7,8) by treatment with aqueous ethanolic sodium hydroxide. Compounds(5,6, and 7) were screened against CCRF-CEM leukemic cells and found to be significantly less active than DDATHF, one of the most active compounds for this system.

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