合成路线1

A new method for the synthesis of encainide has been reported: The acylation of methyl anthranilate (I) with 4-anisoyl chloride (II) by means of NaOH in methylene chloride gives methyl N-(p-anisoyl)anthranilate (III), which is condensed with 2-picoline (IV) by means of n-butyllithium in THF yielding 2-(2-pyridylacetyl)-p-anisanilide (V). Finally, this compound is reduced with H2 over Pt/C then with Pd/C, treated with formaldehyde and reduced again with H2 over Pt/C.

合成路线2

Synthesis of the intermediate 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one (IV) is accomplished by condensation of 3-amino-2-chloropyridine (I) and the anthranilic ester (II) using potassium tert-butoxide as a catalyst. The resulting anthranilic amide (III) is cyclized under the influence of catalytic amounts of sulfuric acid. Treatment of (IV) with chloroacetylchloride in toluene furnishes the corresponding chloroacetamide (V). The diamine part of AF-DX 116 is prepared starting from 2-(hydroxymethyl)piperidine (VI). Reaction with thionylchloride in dichloromethane affords the pipecolylchloride hydrochloride (VII), which is converted with diethylamine to the required 2-[(diethylamino)methyl]piperidine (IX) via nucleophilic ring opening of the intermediate aziridine (VIII). Minor amounts of 3-(diethylamino)hexahydroazepine (X), formed by a side reaction, are separated by thorough fractional distillation of the diamine (IX) and/or recrystallization of its hydrochloride (XI). Coupling of (V) and (XI) in the presence of sodium carbonate yields AF-DX 116 as its free base.

合成路线3

The cyclization of methyl 2-aminobenzoate (I) with 2,5-dimethoxytetrahydrofuran (II) in refluxing acetic acid gives methyl 2-(pyrrol-1-yl)benzoate (III), which by reduction with LiAlH4 in ether is converted into 2-(pyrrol-1-yl)benzyl alcohol (IV). The cyclization of (IV) with ethyl 2-oxopropionate (V) by means of butyllithium and tetramethylethylenediamine (TMEDA) in THF affords 4-methyl-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepine-4-carboxylic acid ethyl ester (VI), which is hydrolyzed with NaOH in refluxing ethanol to the corresponding free acid (VII). The condensation of (VII) with 1-(piperidin-4-yl)-2,3-dihydro-1H-benzimidazol-2-one (VIII) by means of carbonyldiimidazol (CDI) in THF gives 1-[1-(4-methyl-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-ylcarbonyl) piperidin-4-yl]-2,3-dihydro-1H-benzimidazol-2-one (IX), which is finally reduced with LiAlH4 in THF, and treated with maleic acid in acetone.

合成路线4

Synthesis of the intermediate diazepinone (IV) is accomplished by a one-pot synthesis. Condensation of 2-chloro-3-aminopyridine (I) with the anthranilic ester (II) is effected in the presence of potassium tert-butoxide as a catalyst. The resulting anthranilic amide (III) is cyclized under the influence of catalytic amounts of sulfuric acid. Treatment of (IV) with chloroacetylchloride in toluene yields the corresponding choroacetamide (V). The side chain of AQ-RA 741 is prepared starting from 4-picoline, which is alkylated by reaction with 3-(diethylamino)propylchloride in the presence of n-butyllithium. Hydrogenation of (VIII) using platinum dioxide as a catalyst furnishes the diamine (IX), which is coupled with (V) in the presence of catalytic amounts of sodium iodide in acetone leading to AQ-RA 741 as its free base.

合成路线5

The acylation of methylanthranilate (I) with isobutyryl chloride (II) gives 2-isobutyramidobenzoic acid methyl ester (III), which is reduced with LiAlH4 to 2-(isobutylamino)benzyl alcohol (IV). The methylation of (IV) with dimethyl sulfate yields 2-(N-isobutyl-N-methylamino)benzyl alcohol (V), which is treated with SOCl2 to afford the corresponding benzyl chloride (VI). The condensation of (VI) with benzimidazole-2-thiol (VII) by means of NaOH yields 2-[2-(N-isobutyl-N-methylamino)benzylsulfanyl)benzimidazole (VIII), which is finally oxidized with m-chloroperbenzoic acid (MCPBA) as usual.

合成路线6

The reaction of methyl anthranilate (I) with tetrahydrofuran-2,4-dione (II) by means of HCl in ethanol gives 2-(5-oxo-2,5-dihydrofuran-3-ylamino)benzoic acid methyl ester (III), which is cyclized by means of polyphosphoric acid (PPA) at 130-140 C yielding the tricyclic hydroxyketone (IV). The condensation of (IV) with 4-(2-aminoethyl)-1-benzylpiperidine (V) in N-methyl-2-pyrrolidone by a Dean-Stark elimination of water affords 2-[2-(1-benzyl-piperidin-4-yl)ethyl]-9-hydroxy-2,3-dihydro-1H-pyrrolo[3,4-b]quinolin-1-one (VI), which is finally methylated with diazomethane in methanol.

合成路线7

4-[6-(Cyclohexyloxy)-2-naphthyloxy]phenylacetic acid (I) was converted to acid chloride (II) by treatment with oxalyl chloride and catalytic DMF. Subsequent coupling of (II) with methyl anthranilate (III) produced the corresponding amide (IV). The methyl ester group of (IV) was finally hydrolyzed with LiOH in THF-MeOH.

合成路线8

Benzothiadiazine dioxide (II) was prepared by cyclization of methyl anthranylate (I) with sulfamoyl chloride, followed by aqueous NaOH. After silylation of (II) by means of hexamethyldisilazane, alkylation with benzyloxymethyl acetate (III) in the presence of boron trifluoride etherate produced the 3-(benzyloxymethyl)benzothiazine (IV). Further alkylation of (IV) with benzyl bromide in aqueous NaHCO3 furnished the title compound.

合成路线9

Benzothiadiazine S,S-dioxide (II) was obtained by a two-step condensation of methyl anthranylate (I) and sulfamoyl chloride following a reported procedure (1). The alkylation of (II) with 3,4-dichlorobenzyl chloride (III) in the presence of NaHCO3 furnished the title compound.

合成路线10

Methyl anthranilate (I) was condensed with chloral hydrate and hydroxylamine to produce the hydroxymino acetamide (II), which was cyclized to the required isatin-7-carboxylic acid (III) in hot concentrated sulfuric acid. The Pfitzinger condensation of isatin (III) with 7-methyl-1-indanone (IV) gave rise to indenoquinoline (V). Ketone (VI) was then obtained by oxidation of (V) with potassium permanganate in the presence of sodium carbonate. Subsequent thermal decarboxylation of diacid (VI) afforded monocarboxylic acid (VII) (1). After activation of acid (VII) as the corresponding imidazolide (VIII) upon treatment with N,N'-carbonyl diimidazole, coupling with tetraamine (IX) furnished the title bisamide.

合成路线11

1) Condensation of 2-trifluoromethylaniline (I) with ethyl ethoxymethylenemalonate (II) at 125 C to give ethyl-alpha-carbethoxy-beta-(2-trifluoromethylanilino)acrylate (III), m.p. 94 C; this product is cyclized by refluxing with diphenyl ether affording 3-carbethoxy-4-hydroxy-8-trifluoromethylquinoline (IV), m.p. 216 C, which in turn, is hydrolyzed with refluxing aqueous NaOH to the corresponding acid (V), m.p. 290-2 C; this acid is decarboxylated by refluxing in diphenyl ether to 4-hydroxy-8-trifluoromethylquinoline (VI), m.p. 180 C; this product by refluxing with POCl3 is converted into chloro-8-trifluoromethylquinoline (VII), m.p. 78 C; the condensation of quinoline (VII) with methyl anthranilate (A) by means of aqueous 2N HCl affords 4-(2-methoxycarbonylphenylamino)-8-trifluoromethylquinoline (VIII), m.p. 176 C (1,2). The transesterification of methyl ester (VIII) with glycerol affords the final product. (1) 2) Transesterification of methylester (VIII) with 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane (B) to give the acetoneketal of floctafenine (IX), mp 108 C which is finally hydrolized with HCl. (2) 3) Condensation of the chloroquinoline (VII) with the 2,2-dimethyl-4-hydroxymethyl-2,3-dioxolane ester of anthranilic acid by means aqueous HCl to give the already obtained acetoneketal (IX), which is finally hydrolized as before. (2)

合成路线12

合成路线13

Amination and cyclization of methyl 2-aminobenzoate (I) with acetonitrile in the presence of HCl at reflux gives 2-methyl-4-quinazolinone (II), which by chlorination by means of POCl3 in the presence of DIEA in refluxing toluene or in the absence at 120 °C yields 4-chloro-2-methylquinazoline (III). Finally, intermediate (III) is condensed with N-(4-methoxyphenyl)-N-methylamine (IV) in the presence of HCl in isopropanol .

合成路线14

合成路线15