Reaction #2271666

Reaction equation

α-chloro-2-bromobenzaldehyde phenylsulfonylhydrazone

N-methylpiperazine

→

brown gum

Yield 124.8%

1[[(Phenylsulfonyl)hydrazono]-(2- bromophenyl)methyl]-4-methylpiperazine

Yield 124.8%

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   workup.WAITto stand at ambient temperature for 16 hours
2. 2
   TemperatureThe reaction was chilled in an ice bath
3. 3
   Filtrationfiltered
4. 4
   Otherto remove the piperazine hydrochloride that
5. 5
   Otherwas formed
6. 6
   ConcentrationThe filtrate was concentrated
7. 7
   Otherto yield a brown gum
8. 8
   OtherThe gum was triturated with hot acetonitrile
9. 9
   Temperaturethe mixture was cooled in an ice bath
10. 10
    Filtrationwhen cold, was filtered
11. 11
    Otherto remove unwanted side product
12. 12
    ConcentrationThe filtrate was then concentrated

Procedure

To a stirred solution, under nitrogen, of α-chloro-2-bromobenzaldehyde phenylsulfonylhydrazone (271.1 g, 720 mmol) in tetrahydrofuran (THF; 2 L), was added dropwise N-methylpiperazine (159.7 g; 1600 mmol). The reaction was stirred at ambient temperature for three hours, and then permitted to stand at ambient temperature for 16 hours. The reaction was chilled in an ice bath, and then filtered to remove the piperazine hydrochloride that was formed. The filtrate was concentrated to yield a brown gum. The gum was triturated with hot acetonitrile, the mixture was cooled in an ice bath, and when cold, was filtered to remove unwanted side product. The filtrate was then concentrated to afford 392.9 g of a brown gum of crude 1-[[(phenylsulfon-yl)hydrazono]-(2-bromophenyl)methyl]-4-methylpiperazine.

Source