CHLOROSULFONATION OF N-PHENYLMORPHOLINE,BENZOTHIAZOLE, 2-METHYL BENZOTHIAZOLE AND TRIPHENYLOXAZOLE

Abstract

N-Phenylmorpholine (1) reacted with chlorosulfonic acid to give the p-sulfonyl chloride (2), which was characterized as the sulfonamides (3–5). Benzothiazole (6) was converted into the sulfonyl chloride (7) by sequential treatment with hot chlorosulfonic acid and thionyl chloride. Reaction of (7) with amines afforded the derivatives (8–10); NMR spectral analysis of the dimethylamide (8) indicated that it was a mixture of the 4- and 7-isomers. Chlorosulfonation of 2-methylbenzothiazole (11) was achieved by heating with chlorosulfonic acid with or without thionyl chloride. The chloride (12) was converted into amides (13–19). Study of the NMR spectra indicated that mixtures of the 5- and 6-isomers were formed. 2,4,5-Triphenyloxazole (20) reacted with chlorosulfonic acid to give either the mono-(21), bis (23) or bis-tris sulfonylchlorides (23, 34); these were converted into 14 sulfonamides. 2-(p-Nitrophenyl)-4,5-diphenyloxazole (41) reacted with hot chlorosulfonic acid to give the bis-sulfonyl chloride (42), characterized as the dimethylsulfonamide (43). Attempts to form the pure monosulfonyl chloride and to mono nitrate 2,4,5-triphenyloxazole (20) were unsuccessful.     

Diborane Reduction of O-(Tert-Butyldimethylsilyi.)galactaramides. A Model Study for Aminoalditol Synthesis

Tert-butyldimethylsilylation of dimethyl galactarate (1) with tert-butylchlorodimethylsilane/imidazole/N,N-dimethylformamide at 25 [ddot]C dimethyl 2,5-bis-O-(tert-butyldimethylsilyl)galactarate (2) as the principal product, with methyl 2,3,5-tris-O-(tert-butyldimethylsilyl)-D,L-galactarate-l,4-lactone (3) and methyl 2,3-bis-O-(tert-butyldimethyl)-D,L-galactarate-l,5-lactone (4) as minor products. When the reaction was carried out at 65 [ddot]C, the only product was the 1,4-lactone, 3 Ammonolysis of 2 in methanol gave 2,5-bis-O-(tert-butyldimethyl)-galactaramide (5, 94%), which was conveniently reduced with borane- THF to 1,6-diamino-1,6-dideoxygalactitol, isolated as its dihydrochloride 9. Ammonolysis of 3 in methanol gave a mixture of 5; 2,3,4-tris-O-(tert-butyldimethylsilyl)-D,L-galactaramide (6), 2,3,5-tris-O-(tert-butyldimethylsilyl)-D,L-galactaramide (7), and 2,3,5-tris-Q-(tert-butyldimethylsilyl)-D,L-1,4-lactonogalactaramide (8). Borane-THF reduction of a mixture of 6 and 7 also yielded 9. This study served as a model for the use of O-silylated carbohydrate amides in the preparation of aminodeoxyalditols.     

Nonreducing-Sugar Subunit Analogs of Bacterial Lipid a Carrying the Ester-Bound (3R)-3-(Acyloxy)Tetradecanoyl Group

Abstract

In order to elucidate further the relationship between the composition of the fatty acyl groups in the nonreducing-sugar subunit of bacterial lipid A and its biological activity, 3-O-[(3R)-3-(acyloxy)tetradecanoyl]-2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-4-O-phosphono-D-glucose [GLA-63(R, R) and GLA-64(R, R)], and 3-O-[(3R)-3-(acyloxy)tetradecanoyl]-2-deoxy-4-O-phosphono-2-tetradecanamido-D-glucose [GLA-67(R), GLA-68(R) and GLA-69(R)] have been synthesized. Benzyl 2-[(3R)-3-(benzyloxymethoxy)tetradecanamido]-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranoside (5) and benzyl 2-deoxy-4,6-O-isopropylidene-2-tetradecanamido-β-D-glucopyranoside (6) were each esterified with (3R)-3-dodecanoyloxytetradecanoic acid (1), (3R)-3-tetradecanoyloxytetradecanoic acid (2) or (3R)-3-hexadecanoyloxy-tetradecanoic acid (3), to give 7-11, which were then transformed, by the sequence of deisopropylidenation, 6-O-tritylation and 4-O-phosphorylation, into a series of desired compounds.     

Studies on Structurally Simple α β -Butenolides. IX.1 A Short and Efficient Synthesis of (E)-5-Ethyiidene-2(5H)-Furanone

(E)-5-Ethylidene-2(5H)-furanone has been synthesized in 22% overall yield from sorbic acid as starting material, through a three-step sequence.     

Synthesis of C-Glycosyl α-Glycines

Abstract

A scheme of asymmetric synthesis of C-glycosyl α-glycines is described. Reductive hydrolysis of 2-deoxy-3,5-di-O-p-toluoyl-β D-erythropentofuranose 1-cyanide (4) in the presence of N,N-diphenylethylenediamine gave the imidazolidine 5, which was converted to 2,5-anhydro-3-deoxy-4,6-di-O-p-toluoyl-β-D-allose (3)by acid hydrolysis. The aldehyde (3), chiralamine, benzoic acid and t-butyl isocyanide four component condensation afforded in good yield two diastereomeric adducts (6a and 6b), which were separated by column chromatography and deblocked to furnish 2-deoxy-β-D-erythropentofuranosyl R and S-glycines (1a) and (1b).     

Synthesis of γ-Lactone of 1R-CIS 2,2-Dimethyl-3-(2,2,2-tribromo-1-hydroxyethyl)cyclopropane Carboxylic Acid,A Key Intermediate for Deltamethrin,From (+)-3-Carene

1R-cis-2,2-Dimethyl-3-(2,2-dibromovinyl)cyclopropane carboxylic acid¹ (1), the acid moiety of the highly potent photostable pyrethroid deltamethrin (2) has been obtained either by a Wittig reaction on 1R-cis-caronaldehyde ester (3) employing 1, 1-dibromomethylenetriphenylphosphorane or from the bicyclic tribromo-lactone^2,3 (4) by reaction with zinc and acetic acid. Lactone (4) is thus an important intermediate in the deltamethrin synthesis.     

Studies on the Thioglycosides of N-Acetylneuraminic Acid. 6: Synthesis of Ganglioside GM4 Analogs1

Abstract

Two kinds of ganglioside GM₄ thioanalogs having different fatty acyl groups at the ceramide moiety, (2S, 3R, 4E)-1-O-[3-S-(5-acetamido-3,5-di-deoxy-D-glycero-α-D-galacto-2-nonulopyranosylonic acid)-3-thio-β-D-galacto-pyranosyl]-2-octadecanamido (or -tetracosanamido)-4-octadecene-1,3-diol (12, 13), have been synthesized. Condensation of the trichloroacetimidate 7, derived from 1,2,4,6-tetra-O-acetyl-3-S-(methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-3-thio-β-D-galactopyranose (6) by selective 1-O-deacetylation and subsequent trichloroacetimidation, with (2S, 3R, 4E)-2-azido-3-O-benzoyl-4-octadecene-1,3-diol (4), gave the coupling product (8), which was converted into the title compounds via selective reduction of the azide group, condensation with fatty acids, and removal of the protecting groups.     

A General Synthesis of 2-Methoxy-2-Cyclohexenones

The preparation of octalinone 1 at an early stage of a recent synthesis of valeranone¹ required the use of a Robinson annelation with 1,4-dimethoxy-2-butanone (2a), a methoxymethyl vinyl ketone (3) equivalent. The following syntheses of 2-methoxy-2-cyclohexenones illustrate further examples of the heretofore unexploited reaction.²     

One-Pot Synthesis of Tri-Acetalated Aldohexoses with 1,1-Dialkoxycyclohexane–p-Toluenesulfonic Acid

Abstract

2-Deoxy-d-arabino-hexose (1), 2-acetamido-2-deoxy-d-glucose (2), and 2-deoxy-2-trifluoroacetamido-d-glucose (3) were each treated with 1,1-dimethoxycyclohexane or 1,1-dibenzyloxycyclohexane in 1,4-dioxane in the presence of p-toluenesulfonic acid. The major products were the 1,1-dimethyl or 1,1-dibenzyl acetals (4-9) of 3,4:5,6-di-O-cyclohexylidene-2-deoxy-aldehydo-d-arabino-hexose, and of 2- (acylamino)-3,4:5,6-di-O-cyclohexylidene-2-deoxy-aldehydo-D-glucose. The dibenzyl acetal derivatives were converted, by hydro-genolysis, into the corresponding, acyclic aldehydes (10-12) in good yields.     

Chemical interactions between 2-mercaptobenzazoles and π-acceptors

Summary 2-Mercaptobenzazoles (1a–c) interact with several -acceptors such as tetracyanoethylene (TCNE) 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL) dicyanomethyleneindane-1,3-dione (CNIND), 2,3-dicyano-1,4-naphthoquinone (DCNQ), 9-dicyanomethylene-2,4,7-trinitrofluorene (DTF), and 2,3-dichloro-1,4-naphthoquinone (DCHNQ)via the formation of charge-transfer (CT) complexes to yield various heterocyclic compounds.

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Chemische Wechselwirkungen zwischen 2-Mercaptobenzazolen und -Akzeptoren

Zusammenfassung Die 2-Mercaptobenzazole1a–c reagieren mit verschiedenen -Akzeptoren wie Tetracyanoethylen (TCNE), 2,3-Dichlor-5,6-dicyano-1,4-benzochinon (DDQ), 2,3,5,6-Tetrachlor-1,4-benzochinon (CHL), Dicyanomethylenindan-1,3-dion (CNIND), 2,3-Dicyano-1,4-naphthochinon (DCNQ), 9-Dicyanomethylen-2,4,7-trinitrofluoren (DTF) und 2,3-Dichlor-1,4-naphthochinon (DCHNQ) unter Ausbildung von charge transfer — Komplexen (CT) zu heterocyclischen Verbindungen.

     

Synthesis of the Four Configurational Isomers of N-Benzoyl-2, 3, 6-Trtdeoxy-3-C-Methyl-3-Amino-L-Hexose from the (2S, 3R)-Diol Obtained from α-Methylcinnamaldehyde by Fermentation with Baker'S Yeast

Abstract

The erythro and threo chiral C₅ methyl ketones (4) and (5), prepared from the (2S, 3R)-methyl diel (1b), were converted into the phenylsulfenimines (6) and (7), which, in turn, on reaction with allyl-magnesiutn bromide, yielded after acid hydrolysis and benzoylation, the diastereoisomeric C₈-N-aminodiol derivatives (9) and (11), with threo stereochemistry relative to positions 4 and 5. Ozonolysis of (9) and (11) yielded the l-arabino and l-xylo 3-O-methyl branched aminodeoxysugar derivatives (13) and (15), respectively. Using diallylzinc as the reagent, the diastereoisomeric erythro products (8) and (10) were obtained. The latter materials gave the l-ribo-and l-lyxo-(lL-vancosamine) derivatives (12) and (14) upon oxonolysis. The ¹H and ¹³C NMR spectra of the four isomeric aminodeoxysugar derivatives (12)—(15) were discussed.     

The Reaction of Phosphonium Ylids with o-Quinones and Triketones

Abstract

The reaction of 1,2-benzo [a] phenazine-8, 9-dione 1 and/or 1,2,3-indantrione 2, with phosphonium ylides has been studied. When 1 was reacted with two molar amounts of methoxy-(3a) and/or ethoxycarbonylmethylenetriphenylphosphorane (3b), in THF, at the reflux temp, for 3 hrs, dimethyl (4a) and/or diethyl 1,2-dihydrobenzo a furo [3,2-h] phenazine-1,2-dicarboxylate (4b), along with triphenylphosphine oxide and triphenylphosphine were obtained. On the other hand, reaction of equimolar amounts of ylides 3 with the red trione 2 in THF at room temp., afforded colourless crys tals of 2′,4′-dihydroxyspiro [indan-2,3′ (2′H)-indeno [1,2-b] pyran]-1,3,5′(4′H)-trione diacetate (5a) or dipropionate (5b), together with triphenylphosphine oxide. Formation of 6-membered dihydro aromatic ring like 5, is considered as a new reaction of phos phoranes. The structure of the new compounds 4 and 5 was confirmed and the reaction mechanisms are discussed.     

Molecular Engineering of Liquid Crystal Polymers by Living Polymerization. XXIII. Synthesis and Characterization of AB Block Copolymers Based on ω-[(4-Cyano-4′ -Biphenyl)-oxy]alkyl Vinyl Ether, 1H, 1H, 2H, 2H-Perfluorodecyl Vinyl Ether,and 2-(4-Blphenyloxy)ethyl Vinyl Ether with 1H, 1H, 2H, 2H-Perfluorodecyl Vinyl Ether

Abstract

This paper describes the synthesis and characterization of AB block copolymers based on ω-[(4-cyano-4′-biphenyl)oxy]alkyl vinyl ether (6-n), with alkyl being ethyl (6-2), propyl (6-3), nonyl (6-9), and undecanyl (6-11), with 1H, 1H, 2H, 2H-perfluorodecyl vinyl ether (CF8), poly[(-6-n)-b-CF8]X/Y (where X/Y refers to the weight ratio of the two segments), and of 2-(4-biphenyloxy)ethyl vinyl ether (BEVE) with 1H,-1H, 2H, 2H-perfluorodecyl vinyl ether, poly[BEVE-b-CF8]X/Y. They were prepared by living cationic polymerization and exhibit a narrow molecular weight distribution. All block copolymers display a micro-phase-separated morphology when the A segment is in the liquid crystalline phase. Block copolymers based on 6-2, 6-3, and BEVE with CF8 also exhibit a microphase-separated morphology in the melt phase of A and B blocks.     

A Facile Synthesis of 2-Aminonicotinaldehyde

A synthesis of 2-aminonicotinaldehyde (1) which does not require chromatography and is easily scaled up has been developed. Bromination of 2-amino-3-picoline, protected as a phthalimide (4), produced the gem-dibromide (5), which was reacted with Nh₄OH. The imine intermediate (7) was hydrolyzed with acid, producing (1) in a 56% conversion from 4.     

An Efficient Synthesis of α-Bromoacetals via a Combined Chemical and Electrochemical Bromination

α-Bromoacetals (1) are valuable precursors in synthesis of α,β-unsaturated carbonyl compounds (2), 1-alkoxybutadienes² (3), ketene acetals³ (4), 2-methoxyallyl bromides⁴ (5) and other compounds. Because of our interest in the chemistry^5,6 of 3 and 4 we attempted to improve known procedures for the preparation of 1 with the aim to get a short and efficient synthesis of these compounds.     

Synthesis of Bicyclo[4.2.0]Octa-3,7-Diene-2,5-Diones

The bicyclo[4.2.0]octa-3,7-diene-2,5-diones (1) are of interest in that they are valence isomers of 1,4-cyclooctatetraenoquinones. The most obvious route for the formation of such compounds is the [2+2] photoaddition of alkynes to p-benzoquinones. Such a reaction has been observed in the case of 1,4-naphthoquinones. With p-benzoquinones, however, it has been observed in the case of 2-methoxy-p-benzoquinone (2a) alone, while p-benzoquinone (2b) and chloranil (2c) give products derived from addition of acetylenes to a carbonyl rather than an ethylenic bond; ^3,4 such products also accompany the products from 1,4-naphthoquinones referred to above.^1,3     

The Reaction of N-Phenyliminoketenylidenetriphenyl-phosphorane with α,β-Unsaturated Carbonyl Compounds. Synthesis of New Pyran Derivatives

Abstract

The reaction of N-phenyliminoketenylidenetriphenylphosphorane [a] (1), with 2-benzylidene-1, 3-indandione (2), 1,2-diphenyl-3,4-pyrazolidenedione (3)and/or 5-benzylidene barbituric acid (4) has been investigated. When ylide 1 was allowed to react with compounds 2, 3 or 4 in THF at ambient temp. the corresponding new pyrano-phosphoranylidenes 5, 6 or 7 were obtained. The elemental microanalyses, IR, ¹H NMR, ³¹P NMR and MS data agree with the structure of the cyclic iminophosphoranes by [4+2]-cycloaddition and exclude 4-membered ring structure by [2+2]-cycloaddition. When the Wittig reaction was carried on the pyrano-phosphoranes 5, 6 or 7 using p-nitrobenzaldehyde, the exocyclic olefins together with triphenylphosphine oxide were isolated.     

Solid-state structure of (+)-phendimetrazine bitartarate,an anorexic drug

The anorexic drug (+)-(2S, 3S, 4S)-phendimetrazine-2R, 3R)-bitartarate crystallized in the orthorhombic space groupP2₁2₁2₁ and at 293 Ka=7.7710(4),b=13.1379(7),c=15.9913(9) Å,V=1632.6(2) ų,Z=4,R(F)=0.062, andR _w (F)=0.026. A chair conformation 2,3-trans-1,4-oxazine ring with equatorially oriented 2-phenyl,3-methyl, andN-methyl substituents was found as predicted by an earlier reported solid-state CP-MAS¹³C-NMR investigation of crystalline (±)-phendimetrazine bitartarate. The O-CH₂-CH₂-N torsion angle of –58.4(6)° in the solid-state agrees nicely with the 56.0(7)° dihedral angle value estimated by¹H NMR spectroscopy for the major (equatorialN-methyl) phendimetrazine mesylate species in CD₂Cl₂ solution. A common solid-state conformational arrangement was found for (+)-phendimetrazine and a series of six other anorexic drugs structurally analogous to (+)-(2S, 3S)-pseudoephedrine. In this arrangement, NCH(Me)CPh has (S)-configuration, there is a (–)-gaucheMe-CH-C-Ph torsion angle, an antiperiplanarN-CH-C-Ph torsion angle, and the phenyl ring approximately eclipses the C-H bond of the attached carbon (e.g., H-C-C_ipso-C_ortho ca. 4° for 2,3-transphendimetrazine). Nonbonded interactions involving the 3-methyl and the 2-phenyl groups open up the H-C-C_ipso-C_ortho angle in a series of solid-state structures containing the epimeric (–)-(2R, 3S)-ephedrine moiety (e.g., ca. 45° for molecular mechanics calculated 2,3-cis-phendimetrazine model).     

Thermochemical study of some cubane derivatives

The thermochemical study of cubane-1,4-dicarboxylic acid (1), diethyl cubane-1,4-dicarboxylate (2), diisopropyl cubane-1,4-dicarboxylate (3), and bis(2-fluoro-2,2-dinitro)ethyl cubane-1,4-dicarboxylate (4) was performed. The standard enthalpies of combustion (_c H°) and formation (_f H°) of these compounds were estimated using the method of combustion in a calorimetric bomb in an oxygen atmosphere. Using the additive group method, calculated values for _f H° of these substances which agreed satisfactorily with the experimental ones were obtained. The strain energies (E _s) of the cubic structure of derivatives1–4 were calculated. It was concluded thatE _s did not change on substitution of hydrogen atoms in cubane for various functional groups and was equal toE _s of the structure of cubane itself. The reliability of the single published value of _f H° in the cubane crystal state, 541.8 kJ mol^–1 (129.5 kcal mol^–1), was confirmed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2471–2473, October, 1996.     

A Convenient Synthesis of 3-Methoxyphthalic Anhydride

Many antibiotics of the anthracycline family¹ possess structures for which 3-methoxyphthalic anhydride (1) would be a suitable synthon² in a total synthesis. A classic synthesis of (1) has employed 3-nitrophthalic acid³ but, in our hands, proceeded in low overall yield. Recent syntheses have utilized the Diels Alder reaction of dimethyl acetylenedicarboxylate (2) with 1-methoxy-1,3-cyclohexadiene,⁴ 1,4-diacetoxybutadiene,⁵ 2-acetoxyfuran,⁶ 2-methoxyfuran⁷ or furan⁸ to obtain 3-hydroxyphthalic acid or a derivative. We now wish to report a convenient Diels-Alder synthesis of (1) from 3-methoxy-2-pyrone (3).