1-Methylpiperazine → 1-Benzothiophene-2-carbaldehyde

HRID 377373Notes

Reaction equation

HRID 377373 reaction equation
Cl.Cl.CN1CCNCC1.CN1CCNCC1.[S:17]1[C:21]2[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=2[CH:19]=[C:18]1[C:26](O)=[O:27]>C1COCC1>[S:17]1[C:21]2[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=2[CH:19]=[C:18]1[CH:26]=[O:27]

Participants

5

Reactant 3

HCID 531671-MethylpiperazineHCID 95864Benzo(b)thiophene-2-carboxylic acidHCID 27347151-Methylpiperazine dihydrochloride

Product 1

HCID 7365001-Benzothiophene-2-carbaldehydeYield 70.9%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

LiA1H4 (7.6 g, 200 mmol) was suspended under stirring at 0° under Ar in anhydrous THF (400 ml), then N-methylpiperazine dihydrochloride (17.3 g, 100 mmol) was added portionwise in 10 min. N-methylpiperazine (30 g, 300 mmol) was then added dropwise, the mixture was warmed to RT and stirring continued for 2 hours. The surnatant of this suspension was then added by syringe to a stirred solution at 0° under Ar of benzothiophen-2-carboxylic acid (7.13 g, 40.0 mmol) in anhydrous THF (200 ml). The mixture was refluxed for 4 hours and after the same procedure as in preparation 6 pure title compound was obtained (4.6 g, 28.4 mmol, yield 70.9%) as dark orange crystals.

Workup

  1. temperatureThe mixture was refluxed for 4 hours

Sources & evidence

ORD record
ord-b5edde3e7e4e4625a72228748707393c
Source dataset
uspto-grants-2000_02
Patent number
US06025390

Reaction notes

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