6-chlorohexan-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To 11.8 g of 7-allyl-3-methyl-1-(5-oxyhexyl)-xanthine (prepared by alkylation of 7-allyl-3-methylxanthine with 1-chlorohexan-5-one in dimethylformamide in the presence of potassium carbonate at 100° C. for 5 hours; melting point: 71° C.), dissolved in 200 ml of ethanol, 1.5 g of sodium borohydride was added slowly under stirring at a temperature of max. 30° C. After stirring at room temperature for 6 hours the mixture was evaporated under reduced pressure. The residue was extractively worked up with dilute sodium hydroxide solution and with methylene chloride. The combined methylene chloride phases were washed with water, dried and evaporated under reduced pressure. The residue was purified by means of chromatography on silica gel (mobile phase: methylene chloride/ethanol/ammonia-solution (28%), volume ratio 8:2:0.2) and by recrystallization from methylene chloride/diethylether. 30° C After stirring at room temperature for 6 hours the mixture was evaporated under reduced pressure The combined methylene chloride phases were washed with water dried evaporated under reduced pressure The residue was purified by means of chromatography on silica gel (mobile phase: methylene chloride/ethanol/ammonia-solution (28%), volume ratio 8:2:0.2) and by recrystallization from methylene chloride/diethylether

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

Procedure: 1,3-Diethyl-7-(5-oxohexyl)xanthine (melting point 68-69° C.) is prepared from 1,3-diethylxanthine and 1-chloro-hexan-5-one.

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

Procedure: 3-Ethyl-1-(5-oxohexyl)-7-propylxanthine (melting point 81-82° C.) is prepared from 3-ethyl-7-propylxanthine and 1-chlorohexan-5-one.

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

Procedure: 3-Ethyl-1-(5-oxohexyl)-7-propylxanthine (melting point 81-82° C.) is prepared from 3-ethyl-7-propylxanthine and 1-chlorohexan-5-one.

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

Procedure: Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was prepared from 6-chloro-2-hexanone (50.0 g, 357 mmol) and diethyl oxalate (48.4 mL, 357 mmol) according to the procedure described in Part A of Example 19 using methyl hydrazine (19.0 mL, 357 mmol) in place of ethylhydrazine oxalate. Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was isolated as a dark oil that was used without purification in the next step.

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

Procedure: The compound was also accessible, inter alia, by first reacting 7-benzyl-3-methylxanthine with 1-chloro-5-hexanone under the reaction conditions described above to give 7-benzyl-3-methyl-1-(5-oxohexyl)-xanthine (yield 90.4% of theory, melting point: 82°-84° C.) and then reductively methylating the oxohexyl side chain with methylmagnesium chloride in anhydrous ether analogously to Example 9 (yield: 60.2% of theory; melting point: 108°-110° C.). under the reaction conditions

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

Procedure: Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was prepared from 6-chloro-2-hexanone (50.0 g, 357 mmol) and diethyl oxalate (48.4 mL, 357 mmol) according to the procedure described in Part A of Example 19 using methyl hydrazine (19.0 mL, 357 mmol) in place of ethylhydrazine oxalate. Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was isolated as a dark oil that was used without purification in the next step.

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

Procedure: Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was prepared from 6-chloro-2-hexanone (50.0 g, 357 mmol) and diethyl oxalate (48.4 mL, 357 mmol) according to the procedure described in Part A of Example 19 using methyl hydrazine (19.0 mL, 357 mmol) in place of ethylhydrazine oxalate. Ethyl 5-(4-chlorobutyl)-1-methyl-1H-pyrazole-3-carboxylate was isolated as a dark oil that was used without purification in the next step.