Water → 1-(4-Bromophenyl)-4-ethylpiperazine

To a stirred mixture of 1-(4-bromophenyl)piperazine (4.82 g, 20 mmol) and K2CO3 (5.44 g, 40 mmol) in acetone (200 mL) was added iodoethane (2.58 mL, 32 mmol) dropwise over 1 min. After addition, the resulting mixture was stirred at rt for 24 h. The resulting precipitate was filtered off and rinsed with EtOAc (2×30 mL). The filtrate was concentrated to dryness to give a white solid which was treated with H2O (60 mL). Extraction with EtOAc (100 mL+60 mL) followed by concentration gave the crude title compound as a white solid. Trituration with MeOH (40 mL) gave first crop as a white solid (1.30 g). The mother liquor was concentrated to dryness and the trituration was repeated with MeOH, hexane and H2O to give additional 3.60 g as white solid. Total: 4.90 g (91%). 1H NMR (400 MHz, DMSO-d6) δ 6.20 (d, J=7.6 Hz, 2H), 6.87 (d, J=7.6 Hz, 2H), 3.13-3.03 (m, 4H), 2.49-2.40 (m, 4H, partially overlapping with DMSO signal), 2.34 (q, J=6.8 Hz, 2H), 1.01 (t, J=6.8 Hz, 3H); MS ESI 269.0 [M+H]+, calcd. for [C12H17BrN2+H]+ 269.1

1. additionAfter addition
2. filtrationThe resulting precipitate was filtered off
3. washrinsed with EtOAc (2×30 mL)
4. concentrationThe filtrate was concentrated to dryness
5. customto give a white solid which
6. extractionExtraction with EtOAc (100 mL+60 mL)
7. concentrationfollowed by concentration
8. customgave the crude title compound as a white solid

ORD record

ord-4e5d7dbcfafc43a7af2cb8d8ff32a649

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08999968B2