合成路线1

A new synthesis of adinazolam has been described: The condensation of phthaloyl-glycyl chloride (I) with 2-amino-5-chlorobenzophenone (II) in refluxing toluene gives 4-chloro-2-(phthaloylglycylamido)benzophenone (III), which is cyclized by means of hydrazine in refluxing ethanol yielding 7-chloro-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-2-one (IV). The reaction of (IV) with P2S5 in hot pyridine affords the corresponding thione (V), which is finally cyclized with N,N-dimethylglycine hydrazide by means of triethylamine in refluxing butanol. The starting products (I) and (II) are obtained as follows: The reaction of N-(ethoxycarbonyl)phthalimide (VI) with glycine by means of Na2CO3 in water gives the N-phthaloylglycine (VII), which is then treated with refluxing SOCl2 to give (I). The protection of 2-amino-4-chlorobenzoic acid (VIII) with tosyl chloride gives the corresponding N-tosyl derivative (IX), which by reaction with refluxing SOCl2 is converted into the acyl chloride (X). Finally, this compound is submitted to a Friedel-Craft's condensation with benzene and AlCl3 to afford (II).

合成路线2

A new scaleable two-step synthesis of thalidomide was reported: The reaction of L-glutamine (I) with N-(ethoxycarbonyl)phthalimide (II) gives the N-phthaloyl-L-glutamine (III), which is finally cyclized by means of carbonyldimidazole (CDI) and dimethylaminopyridine.

合成路线3

The condensation of 3,4-dimethoxybenzaldehyde (I) with glycine (II) by means of KOH in hot methanol gives racemic threo-3-(3,4-dimethoxyphenyl)serine (III), which is acylated with N-(ethoxycarbonyl)phthalimide (IV) by means of Na2CO3 in water yielding the corresponding N-phthaloyl derivative (V). The reaction of (V) with AlCl3 and ethyl mercaptan in dichloromethane affords N-phthaloyl-3-(3,4-dihydroxyphenyl)serine (VI), which is deprotected with hydrazine in refluxing ethanol to racemic threo-3-(3,4-dihydroxyphenyl)serine (VII). The resolution of the racemic form (VII) is performed through its benzyloxy derivative.

合成路线4

3) The condensation of 2(S)-phthalimido-4-(triphenylmethoxy)butyric acid (XVII) with 2(S)-amino-6,6-dimethoxyhexanoic acid methyl ester (XVIII) by means of BOP in methylene chloride gives the corresponding amide (XIX), which is treated with p-toluenesulfonic acid in methanol to eliminate the trityl group, yielding (XX) with a free hydroxy group. The reaction of (XX) with thioacetic acid by means of triphenylphosphine/diisopropyl azidodicarboxylate in THF affords the thioacetate (XXI), which is cyclized with sodium methoxide in methanol as before, giving the protected pyridothiazepinone (XXII). Finally, this compound is deprotected with hydrazine in methanol to afford the previously reported intermediate (VI). 4) The intermediates 2(S)-phthalimido-4-(triphenylmethoxy)butyric acid (XVII) and 2(S)-amino-6,6-dimethoxyhexanoic acid methyl ester (XVIII) have been obtained as follows: 4a) The condensation of L-homoserine (XXIII) with phthalimide-N-carboxylic acid ethyl ester (XXIV) by means of Na2CO3 in water gives 4-hydroxy-2(S)-phthalimidobutyric acid (XXV), which is then treated with trityl chloride and triethylamine in chloroform to yield intermediate (XVII). 4b) The condensation of 6-hydroxy-L-norleucine (XVI) with phthalimide (XXIV) as before gives 6-hydroxy-2(S)-phthalimidohexanoic acid (XXVI), which is esterified with methyl iodide/Cs2CO3 in DMF to yield the methyl ester (XXVII). The oxidation of (XXVII) with oxalyl chloride in dichloromethane affords aldehyde (XXVIII), which is treated with trimethyl orthoformate/p-toluenesulfonic acid to give the dimethylketal (XXIX). Finally, this compound is deprotected with hydrazine in methanol, yielding intermediate (XVIII).

合成路线5

The reaction of (S)-2-amino-6-hydroxyhexanoic acid (I) with N-(ethoxycarbonyl)phthalimide (II) by means of Na2CO3 in water gives 6-hydroxy-2(S)-(phthalimido)hexanoic acid (III), which is esterified with benzyl bromide and Cs2CO3 in DMF yielding the benzyl ester (IV). The oxidation of the terminal OH group of (IV) with (COCl)2 in dichloromethane affords the aldehyde (V), which is methylated with AlMe3 in dichloromethane giving 6-hydroxy-2(S)-(phthalimido)heptanoic acid (VI). The oxidation of (VI) with oxalyl chloride as before yields the ketone (VII), which is methylated with TiCl4 and methylmagnesium chloride to provide the carbinol (VIII). The reaction of (VIII) with trimethylsilyl azide in dichloromethane gives the azido derivative (IX), which is cyclized by reduction with H2 over Pd/C in DMF yielding the perhydroazepinone (X). Elimination of phthalimido protecting group of (X) with hydrazine in methanol/dichloromethane affords 3(S)-amino-7,7-dimethylperhydroazepin-2-one (XI), which is protected with trityl chloride and TEA in dichloromethane to give the tritylamino compound (XII). The condensation of (XII) with ethyl 2-bromoacetate (XIII) by means of LHMDS, followed by deprotection with TFA affords the adduct (XIV) with a free amino group, which is acylated with 2(R)-benzyl-3-(benzyloxyamino)propionic acid (XV) by means of HOBT and EDAD in dichloromethane providing the amide (XVI). The formylation of (XVI) with formic acid and acetic anhydride gives the formamide (XVII), which is deprotected with H2 over Pd/C in ethanol yielding intermediate (XVIII). Finally, this compound is hydrolyzed with NaOH in methanol.

合成路线6

The reaction of phthalimidocarboxylic acid ethyl ester (I) with 2-(2-aminoethoxy)ethanol (II) in THF gives N-[2-(2-hydroxyethoxy)ethyl]phthalimide (III), which is oxidized with CrO3/sulfuric acid in acetone yielding 2-(phthalimidoethoxy)acetic acid (IV). The condensation of (IV) with L-alanyl-D-isoglutamine benzyl ester (V) by means of phenylphosphoryl azide (DPPA) and triethylamine in DMF gives N-[2-(2-phthalimidoethoxy)acetyl]-L-alanyl-D-isoglutamine benzyl ester (VI), which is finally debenzylated by hydrogenation over Pd/C in acetic acid.

合成路线7

Condensation of veratraldehyde (I) with malonic acid and ammonium acetate in refluxing EtOH afforded 3-amino-3-(3,4-dimethoxyphenyl)propionic acid (II). The N-phthaloyl group was introduced in (II) by treatment with N-carbethoxyphthalimide (III) in the presence of Na2CO3. The resulting phthalimido acid (IV) was converted to the title amide via activation with carbonyl diimidazole, followed by treatment with ammonium hydroxide.

合成路线8

Diazotization of 4-tert-butylaniline (I) with NaNO2 and HCl, followed by reduction of the resulting diazonium salt with SnCl2 provided hydrazine (II). Fisher indolization with 4-chlorobutyraldehyde (IV), (obtained by hydrogenation of acid chloride (III)), then afforded tryptamine (V). In an alternative procedure, 4-phthalimidobutyraldehyde diethyl acetal (VIII) was prepared by treatment of amine (VI) with N-carbethoxyphthalimide (VII). Fisher reaction of (VII) with hydrazine (II) produced the (phthalimidoethyl)indole (IX), which was deprotected with hydrazine to furnish the corresponding tryptamine (V). Subsequent condensation of (V) with di-tert-butyl dicarbonate gave carbamate (X). This was finally reduced by means of LiAlH4 providing the target N-methyl tryptamine.

合成路线9

Diazotization of 4-tert-butylaniline (I) with NaNO2 and HCl, followed by reduction of the resulting diazonium salt with SnCl2 provided hydrazine (II). Fisher indolization with 4-chlorobutyraldehyde (IV), (obtained by hydrogenation of acid chloride (III)), then afforded the target tryptamine. In an alternative procedure, 4-phthalimidobutyraldehyde diethyl acetal (VII) was prepared by treatment of amine (V) with N-carbethoxyphthalimide (VI). Fisher reaction of (VII) with hydrazine (II) produced the (phthalimidoethyl)indole (VIII), which was deprotected with hydrazine to furnish the corresponding tryptamine.

合成路线10

Diazotization of 4-tert-butylaniline (I) with NaNO2 and HCl, followed by reduction of the resulting diazonium salt with SnCl2 provided hydrazine (II). Fisher indolization with 4-chlorobutyraldehyde (IV), (obtained by hydrogenation of acid chloride (III)), then afforded tryptamine (V). In an alternative procedure, 4-phthalimidobutyraldehyde diethyl acetal (VIII) was prepared by treatment of amine (VI) with N-carbethoxyphthalimide (VII). Fisher reaction of (VII) with hydrazine (II) produced the (phthalimidoethyl)indole (IX), which was deprotected with hydrazine to furnish the corresponding tryptamine (V). Finally, dimethylation of (V) by means of methyl methanesulfonate provided the target N,N-dimethyl tryptamine.

合成路线11