2-(3,4-DIMETHOXY-PHENYL)-PIPERAZINE synthesis

5synthesis methods

Product Name:2-(3,4-DIMETHOXY-PHENYL)-PIPERAZINE
CAS Number:65709-39-9
Molecular formula:C12H18N2O2
Molecular Weight:222.28

Piperazine, 2-(3,4-dimethoxyphenyl)-1,4-bis(phenylmethyl)-

1421005-05-1
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65709-39-9
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Yield:65709-39-9 88%

Reaction Conditions:

with palladium on activated charcoal;hydrogen in methanol; for 4 h;

Steps:

General procedure for the synthesis of piperazines

General procedure: Olefins 1 (1 mmol) were dissolved in dry THF (15 mL) under N₂ and HgO·2HBF₄ (1.1 mmol) was added portionwise followed by the addition of N,N′-disubstitutedethylene diamine 2 (1.5 mmol). The reaction mixture was stirred at 70 °C for the appropriate time as shown in Table 1. After completion of the reaction, as indicated by TLC, the reaction mixture was diluted with water and extracted with CH₂Cl₂ (3 × 30 mL). The combined organic layers were dried over anhydrous Na₂SO₄, concentrated in vacuo, and purified by flash column chromatography on silica gel to afford corresponding protected piperazine derivatives 3. The compound 3 was dissolved in MeOH (9 mL) containing acetic acid (1 mL) and then added Pd/C.²⁷ The reaction mixture was stirred for 4 h under H₂ on a Parr hydrogenator and the progress of the reaction was monitored on TLC. After completion of reaction, the catalyst was filtered off and the organic mixture was evaporated in a rota-vapour. The crude mixture was purified by column chromatography using chloroform:methanol (95:5-80:20) as eluting mixture to get the corresponding product 4. The products reported herein, were characterized by ¹H NMR, ¹³C NMR, and mass spectroscopy. The spectroscopic data of the compounds are in agreement with those reported in the literature.²⁹ Spectral data for 3a^29a-d. ¹H NMR (400 MHz, CDCl₃): δ 1.92-2.14 (m, 4H), 2.14-2.66 (m, 2H), 3.82 (s, 4H), 4.14 (m, 1H), 7.01-7.49 (m, 15H); ¹³C NMR: δ 29.4, 36.5, 41.4, 62.5, 125.80, 127.40, 128.41, 144.70; MS (ESI): 342 (M⁺).