(2,4-dichlorophenyl)hydrazine

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:

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

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

Procedure: 2-Chloro-6-(2,4-dichlorophenylhydrazino)-9-cyclopentylpurine is prepared from 2,6-dichloro-9-cyclopentylpurine, 2,4-dichlorophenylhydrazine, and triethylamine essentially as described above in Example 1, Scheme A, step b.

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

Procedure: A mixture of 2,4-dichlorophenylhydrazine (1.0 g, 4.7 mmol), ethyl pyruvate (0.53 mL, 4.7 mmol), triethylamine (0.65 mL, 4.7 mmol) and ethanol (5 mL) was heated at reflux overnight. The solvent was evaporated and the residue taken up in chloroform. The solution was washed with water and brine and dried over magnesium sulfate and concentrated, leaving an oil (1.1 g, 98%). was heated at reflux overnight The solvent was evaporated The solution was washed with water and brine dried over magnesium sulfate concentrated

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

Procedure: 105.0 g (1.05 mol) of ethyl acrylate is added dropwise to a mixture of 37.3 g (211 mmol) of 2,4-dichlorophenylhydrazine, 18.6 g (273 mmol) of sodium ethoxide, 150 ml of ethanol and 150 ml of toluene and the mixture is subsequently stirred for 1 hour. The reaction mixture is evaporated to 100 ml and the residue is taken up in water. The organic phase is separated off and extracted with 5% strength NaOH. The combined aqueous phases are adjusted to a pH of 6.5 and the solid formed is filtered off with suction, washed with water and dried under reduced pressure. The reaction mixture is evaporated to 100 ml The organic phase is separated off extracted with 5% strength NaOH the solid formed is filtered off with suction washed with water dried under reduced pressure

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

Procedure: 105.0 g (1.05 mol) of ethyl acrylate is added dropwise to a mixture of 37.3 g (211 mmol) of 2,4-dichlorophenylhydrazine, 18.6 g (273 mmol) of sodium ethoxide, 150 ml of ethanol and 150 ml of toluene and the mixture is subsequently stirred for 1 hour. The reaction mixture is evaporated to 100 ml and the residue is taken up in water. The organic phase is separated off and extracted with 5% strength NaOH. The combined aqueous phases are adjusted to a pH of 6.5 and the solid formed is filtered off with suction, washed with water and dried under reduced pressure. The reaction mixture is evaporated to 100 ml The organic phase is separated off extracted with 5% strength NaOH the solid formed is filtered off with suction washed with water dried under reduced pressure

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

Procedure: A mixture of 7.8 g. of 2,4-dichlorophenylhydrazine (prepared from 2,4-dichlorohydrazine hydrochloride by treatment with 1 N sodium hydroxide), 9.9 g. of crotononitrile and 3 drops of choline (45% in methanol) is heated on a steam bath for 18 hours. The solution is mixed with 200 ml. of water then 20 ml. of concentrated hydrochloric acid is added and the mixture is refluxed for 1/2 hour, cooled and made basic with 10% sodium hydroxide to give a gummy solid. The solid is placed on a chromatography column containing 300 g. of a 200 mesh synthetic magnesium silicate adsorbent. The column is eluted with 1% acetone-hexane, 5% acetone-hexane and 10% acetone-hexane to remove most of the less polar material. The elution procedure is monitored by thin layer chromatography using the upper phase of a mixture of 2 parts benzene, one part acetone and 2 parts water; then the column is eluted with acetone to remove the crude product as a dark oil which partly crystallizes on standing. This material is chromatographed again using another 200 g. of the magnesium silicate adsorbent and eluting a colored impurity with 5% acetone-hexane. The column is then eluted with 50% acetone-hexane to collect a tan oil which solidifies on standing. The solid is recrystallized 3 times from ether-hexane to give 0.5 g. of the product of the Example as tan crystals, m.p. 109°-111° C. A mixture of 7.8 g The solution is mixed with 200 ml the mixture is refluxed for 1/2 hour cooled to give a gummy solid containing 300 g The column is eluted with 1% acetone-hexane, 5% acetone-hexane and 10% acetone-hexane to remove most of the less polar material The elution procedure the upper phase of a mixture of 2 parts benzene, one part acetone and 2 parts water then the column is eluted with acetone to remove the crude product as a dark oil which partly crystallizes This material is chromatographed again of the magnesium silicate adsorbent and eluting a colored impurity with 5% acetone-hexane The column is then eluted with 50% acetone-hexane to collect a tan oil which The solid is recrystallized 3 times from ether-hexane to give 0.5 g

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

Procedure: 2-Chloro-6-(2,4-dichlorophenyl hydrazino)-9-cyclopentylpurine is prepared from 2,6-dichloro-9-cyclopentylpurine, 2,4-dichlorophenyl hydrazine, and triethylamine essentially as described above in Example 1, Scheme A, step b.