N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]acetamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the aqueous alcoholic solution containing N-acetyl serotonine prepared in Example 2, there were added slowly and simultaneously 36 g of dimethyl sulphate and 20 g of 30% sodium hydroxide so that the pH was maintained at 12.5, while ensuring that the temperature did not exceed 40° C. During this operation, a part of the melatonine formed crystallised and this was filtered after neutralisation. The mother-liquor of crystallisation was decolourised with activated carbon, concentrated to eliminate the ethanol, then extracted with dichloromethane. After separation of the aqueous phase, the organic phase was concentrated to dryness which allowed the recuperation of a further 28 g of crude melatonine. The two fractions, which totalled 42 g, were mixed and purified by recrystallisation in a mixture containing water and ethanol in a 75:25 ratio. 30 g of white crystals of melatonine were obtained having a purity of 98.6%. were added slowly did not exceed 40° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the aqueous alcoholic solution containing N-acetyl serotonine prepared in Example 2, there were added slowly and simultaneously 36 g of dimethyl sulphate and 20 g of 30% sodium hydroxide so that the pH was maintained at 12.5, while ensuring that the temperature did not exceed 40° C. During this operation, a part of the melatonine formed crystallised and this was filtered after neutralisation. The mother-liquor of crystallisation was decolourised with activated carbon, concentrated to eliminate the ethanol, then extracted with dichloromethane. After separation of the aqueous phase, the organic phase was concentrated to dryness which allowed the recuperation of a further 28 g of crude melatonine. The two fractions, which totalled 42 g, were mixed and purified by recrystallisation in a mixture containing water and ethanol in a 75:25 ratio. 30 g of white crystals of melatonine were obtained having a purity of 98.6%. were added slowly did not exceed 40° C

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: N-acetyl serotonin was synthesized as follows. 100 mg (0.47 mmol) serotonin hydrochloride and 10 mL of pyridine were mixed in a 100 mL round-bottomed flask, and the solution was cooled to 0° C. under argon. Acetic anhydride (2.84 g, 28.4 mmol) was added slowly over 1 hr. After stirring at 0° C. for 20 hr the reaction was terminated by removing the volatile reagents under high vacuum. The remaining syrup was dissolved into 25 mL of methylene chloride and washed with 0.1 M HCl until the pH of the aqueous phase was less than 3. The organic phase was dried under anhydrous sodium sulfate, filtered and concentrated to yield a syrup. To this syrup was added 25 mL of aqueous isopropyl alcohol (50 wt%) and the solution was cooled to 0° C. Sodium hydroxide (1 mL of a 1.0 mM solution) was added and stirred at 0° C. for 4 hr. The solution was neutralized with acetic acid, concentrated and filtered through a short plug of silica gel with ether, concentrated and recrystallized from benzene/chloroform to yield 27 mg (0.11 mmol) of N-acetyl serotonin. N-acetyl serotonin was synthesized was terminated by removing the volatile reagents under high vacuum The remaining syrup was dissolved into 25 mL of methylene chloride washed with 0.1 M HCl until the pH of the aqueous phase The organic phase was dried under anhydrous sodium sulfate filtered concentrated to yield a syrup the solution was cooled to 0° C stirred at 0° C. for 4 hr concentrated filtered through a short plug of silica gel with ether concentrated recrystallized from benzene/chloroform

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To N-acetylserotonin (0.9 g; 4 mmol) was added N-methylmorpholine (0.92 ml, 8 mmol), and 4-nitrophenyl chloroformate (1.61 g; 8 mmol) dissolved in tetrahydrofuran. Reaction was carried out for 0.5 h under an argon atmosphere. The solvent was evaporated. The residue was purified by column chromatography (SiO2, methanol/methylene chloride) to give 0.92 g (yield 60%) of crystalline yellow product with a melting point 153-156° C. Reaction The solvent was evaporated The residue was purified by column chromatography (SiO2, methanol/methylene chloride)

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In round bottom flask, melatonin (48 mg, 0.21 mmol) was taken in dry CH2Cl2 (3 ml). The reaction mixture was cooled to −78° C. by keeping in acetone bath with liquid nitrogen. To this chilled reaction mixture boron tribromide (0.12 ml, 12 mmol) was added dropwise and stirring continued at this temperature for another 1 h. Then the reaction mixture was stirred overnight at room temperature for overnight. Completion of reaction was monitored by TLC; the reaction mixture was quenched by addition of water, and 10% Hcl and extracted with ethyl acetate. The combined organic phases were washed with water (20 mL) and brine (10 mL) and dried over sodium sulfate. The organic layer was removed under reduced pressure. The crude product was purified by silica gel column chromatography to give N-(2-(5-hydroxy-1H-indol-3-yl)ethyl) acetamide (5a). Isolated as reddish colored semi solid (20 mg, 45%), by elution with 6% methanol in chloroform. was added dropwise Then the reaction mixture was stirred overnight at room temperature for overnight Completion of reaction the reaction mixture was quenched by addition of water, and 10% Hcl extracted with ethyl acetate The combined organic phases were washed with water (20 mL) and brine (10 mL) dried over sodium sulfate The organic layer was removed under reduced pressure The crude product was purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Serotonin (compound 7 in Scheme 3) reacts with N-succinimidyl acetate (8) selectively on the primary alkyl amine, as shown below, to give N-acetylserotonin (9). The electroactive hydroxytryptamine ring system emerges from the reaction unchanged. In practice a biological sample of 1.0 ml volume (for example: cerebrospinal fluid) is degassed by bubbling argon and treated with 0.05 ml of a solution of N-succinimidyl acetate in dioxane (100 mg/ml). The reaction is carried out at a pH of 10-11 in a closed vessel under argon at 70° C. for a period as short as five minutes or as long as two hours. The reaction is then quenched with glycine, giving the non-electroactive sodium N-acetylglycinate (10). ##STR5##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the aqueous alcoholic solution containing N-acetyl serotonine prepared in Example 2, there were added slowly and simultaneously 36 g of dimethyl sulphate and 20 g of 30% sodium hydroxide so that the pH was maintained at 12.5, while ensuring that the temperature did not exceed 40° C. During this operation, a part of the melatonine formed crystallised and this was filtered after neutralisation. The mother-liquor of crystallisation was decolourised with activated carbon, concentrated to eliminate the ethanol, then extracted with dichloromethane. After separation of the aqueous phase, the organic phase was concentrated to dryness which allowed the recuperation of a further 28 g of crude melatonine. The two fractions, which totalled 42 g, were mixed and purified by recrystallisation in a mixture containing water and ethanol in a 75:25 ratio. 30 g of white crystals of melatonine were obtained having a purity of 98.6%. were added slowly did not exceed 40° C