合成路线1

The reaction of o-chlorophenylacetic acid (I) with SOCl2 gives the corresponding acyl chloride (II), which is condensed with 2-(methylamino) ethanol (III) yielding o-chloro-N-methyl-N-(2-hydroxyethyl)phenylacetamide (IV). The reduction of (IV) with diborane in THF affords N-methyl-N-(2-hydroxyethyl)-2-(2-chlorophenyl)ethylamine (V), which by reaction with PCl5 in CHCl3 is con-verted into N-methyl-N-(2-chloroethyl)-2-(2-chlorophenyl)ethylamine (VI). Finally, this compound is cyclized by means of anhydrous AlCl3-NH4Cl at 175 C.

合成路线2

The condensation of labeled 2-(3-chlorphenyl)acetic acid (I) with N-methylethanolamine (II) by means of SOCl2 gives the corresponding amide (III), which is reduced with BH3, yielding the tertiary amine (IV). The reaction of (IV) with PCl3 affords the chloroethylamine (V), which is finally cyclized by means of AlCl3 to provide the target benzazepine.

合成路线3

beta-Methylaminoethanol (VI) is treated with ethyl chlorocarbonate in triethylamine to give ethyl N-methyl-hydroxyethylcarbamate (VII), which is treated with thionyl chloride to give ethyl-N-methyl-beta-chloroethylcarbamate (VIII). Compound (VIII) is treated with 5H-dibenzo[a,d]cyclohepten-5-one oxime (I) and the resulting product is decomposed without isolation.

合成路线4

In a different method, reaction of styrene oxide (XV) with methylamine provided amino alcohol (XVI), which was further condensed with ethylene oxide (XVII) to afford amino diol (XVIII). Alternatively, diol (XVIII) was prepared by a more direct procedure by condensation of epoxide (XV) with 2-(methylamino)ethanol (XIX). Chlorination of (XVIII) employing SOCl2 yielded the dichloro derivative (XX), which was subsequently condensed with 2-aminobenzyl alcohol (X) leading to piperazine (XXI). Cyclization of (XXI) to the title compound was accomplished by treatment with hot polyphosphoric acid. Optionally, alcohol (XXI) was converted to chloride (XXII), which was then cyclized in the presence of AlCl3. In a related method, alcohol (XXI) was esterified with AcOH, and the resultant acetate ester (XXIII) was then cyclized in the presence of polyphosphoric acid

合成路线5

Elgodipine can be obtained in three main steps: The alkylation of N-methyl-2-aminoethanol (I) with 4-fluorobenzyl chloride (II) gives 2-[N-(4-fluorobenzyl)-N-methylamino]ethanol (III), which is esterified with 2,2,6-trimethyl-4H-1,3-dioxin-4-one (IV) yielding the corresponding acetoacetic ester (V). The condensation of (V) with 2,3-methylenedioxybenzaldehyde (VI) affords 2-[N-(4-fluorobenzyl)-N-methylamino]ethyl 2-(2,3-methylenedioxybenzylidene]acetoacetate (VII), which is finally cyclized with isopropyl 3-aminocrotonate (VIII). The intermediate aldehyde (VI) is obtained starting from 2,3-dimethoxybenzaldehyde (X), which by demethylation with HCl or HBr yields 2,3-dihydroxybenzaldehyde (XI). Finally, this compound is converted into (VI) in the usual way. The intermediate crotonate (VIII) is obtained by reaction of isopropyl acetoacetate (IX) with ammonia.

合成路线6

The reaction of 2-chloropyridine (I) with 2-(methyl-amino)ethanol (II) by heating at 150 C gives 2-[N-methyl-N-(2-pyridyl)amino]ethanol (III), which is condensed with 4-fluorobenzaldehyde (IV) by means of NaH in DMF, yielding 4-[2-[N-methyl-N-(2-pyridyl)amino]-ethoxy]benzaldehyde (V) (1-3). The reaction of (V) with thiazolidine-2,4-dione (VI) by means of piperidinium acetate in refluxing toluene affords 5-[4-[2-[N-methyl-N-(2-pyridyl)- amino]ethoxy]benzylidene]thiazolidine-2,4-dione (VII). Finally, this compound is reduced with H2 over Pd/C (1), Mg in methanol (2,3) or biocatalytically by incubation with whole cells of the yeast Rhodotorula rubra CBS 6469 at pH 7.5-8.0 (4-6). Under acidic conditions, pH 3.0-5.0, this microbial biotransformation is enantioselective, giving the (+)-(R)-enantiomer of rosiglitazone.

合成路线7

Treatment of chromane (I) with metanesulfonyl chloride in pyridine at 0 C afforded mesylate (II), which was treated with 2-methylaminoethanol (III) to afford tertiary amine (IV). Reaction with SOCl2 gave chloride (V), and further reaction with p-hydroxybenzaldehyde (VI) provided (VII). Aldehyde (VII) was then condensed with 2,4-thiazolidinedione (VIII) in the presence of piperidine benzoate in toluene to furnish (IX). Finally, the benzyl protecting group was removed by treatment with acetic acid-hydrochloric acid at 60 C to give the title compound.

合成路线8

A new synthesis of the title compound, very similar to that already published, is reported: The condensation of 6-(benzyloxy)-2,5,7,8-tetramethyl-3,4-dihydro-2H-1-benzopyran-2-ylmethyl methanesulfonate (I) with 2-(methylamino)ethanol (II) by heating at 120 C gives the tertiary amine (III), which is condensed with 4-fluorobenzaldehyde (IV) by means of NaH in DMF yielding the 4-alkoxy benzaldehyde (V). A new condensation of (V) with thiazolidine-2,4-dione (VI) by means of piperidine in refluxing toluene affords the benzyloxy derivative of the target compound (VII). Finally, the target compound is obtained by treatment of (VII) with HCl in acetic acid.

合成路线9

The condensation of 5-(benzyloxy)-2,2,4,6,7-pentamethyl-3,4-dihydrobenzofuran-3-ylmethyl methanesulfonate (I) with 2-(methylamino)ethanol (II) by heating at 120 C gives the tertiary amine (III), which is treated with SOCl2 in benzene yielding the chloroethylamino compound (IV). The condensation of (IV) with 4-nitrophenol (V) by means of K2CO3 in hot DMF affords the 4-nitrophenoxy compound (VI), which is reduced with H2 over Pd/C in ethyl acetate to the corresponding 4-aminophenoxy compound (VII). The condensation of (VII) with ethyl acrylate (VIII) by means of NaNO2 and HBr in methanol/water gives the 2-bromopropionic ester (IX), which is cyclized with thiourea (X) by means of NaOAc in refluxing ethanol yielding the thiazolidinedione (XI). Finally, this compound is debenzylated with HCl in hot acetic acid.

合成路线10

The 2-aminobenzophenone derivative (III) was prepared by condensation of L-tyrosine methyl ester (I) with 2-benzoylcyclohexanone (II) in refluxing anisole, with concomitant dehydrogenation in the presence of Pd/C. Subsequent Mitsunobu coupling of (III) with 2-(N-Boc-N-methylamino)ethanol (V), prepared from aminoalcohol (IV) and Boc2O, afforded the Boc-protected aminoethyl ether (VI). After removal of the Boc group of (VI) by treatment with trifluoroacetic acid, condensation of the resulting secondary amine (VII) with 2-fluoropyridine (VIII) yielded the 2-aminopyridine derivative (IX). Finally, the methyl ester group of (IX) was hydrolyzed to the title carboxylic acid using LiOH.

合成路线11

The formylation of 3,5-dichloropyridine (I) with methyl formate (II), BuLi and DIEA in THF gives 3,5-dichloropyridine-4-carbaldehyde (III), which is treated with 4-bromophenol (IV) and potassium tert-butoxide in hot THF to yield the adduct (V). This compound, without isolation is cyclized with methyl 2-mercaptoacetate (VI) by means of Cs2CO3 to afford 4-(4-bromophenoxy)thieno[2,3-c]pyridine-2-carboxylic acid methyl ester (VII), which is hydrolyzed with LiOH in THF/water to provide the corresponding carboxylic acid (VIII). Finally, this compound is condensed with ethanolamine (IX) by means of EDC and HOBt in DMF to give the target ethanolamide. Alternatively, the target amide can also be obtained by direct reaction of methyl ester (VII) with ethanolamine (IX) in refluxing methanol.

合成路线12

The reaction of 3-phenylphthalide (I) with N-methylethanolamine (II) in refluxing benzene gives N-(2-hydroxyethyl)-2-(1-hydroxy-1-phenylmethyl)-N-methylbenzamide (III), which is cyclized by means of Ts-OH in refluxing toluene to yield 5-methyl-1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocin-6-one (IV). Finally this compound is reduced with LiAlH4 in refluxing THF to afford the target benzoxazocine. In an alternative method, the reduction of 2-benzoyl-N-(2-hydroxyethyl)-N-methylbenzamide (V) by means of sodium bis(2-methoxyethoxy)aluminum hydride in refluxing toluene gives the diol (VI), which is then cyclized by means of Ts-OH in refluxing toluene, or by means of aq. 48% HBr in hot chloroform to afford the target benzoxazocine.

合成路线13

The reaction of 2-benzoylbenzoic acid (I) with PCl3 in dichloromethane gives the corresponding acyl chloride (II), which is condensed with N-methylethanolamine (III) by means of TEA In dichloroethane to yield the amide (IV). The reaction of (IV) with PCl3 in dichloroethane affords the 2-chloroethylamide (V), which is reduced with NaBH4 and A-OH in dichloromethane to provide the diol (VI). Finally, this compound is cyclized by means of aq. HBr in dichloroethane to give the target benzoxazocine.

合成路线14

The title compound is prepared using nocathiacin I (I) as the starting material. Michael addition of 2-(methylamino)ethanol (II) to the conjugated amide function of (I) in aqueous solution gives rise to the target diaminopropionamide derivative.

合成路线15