Piperazine → 2-Piperazin-1-yl-1,3-benzothiazole

HRID 1682365Notes

Reaction equation

HRID 1682365 reaction equation
Cl[C:2]1[S:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.[NH:11]1[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]1>>[N:11]1([C:2]2[S:3][C:4]3[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=3[N:6]=2)[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]1

Participants

3

Procedure

2-Chlorobenzothiazole (5.00 g), is heated in alcohol (75 ml) with 3.05 g piperazine (3.05 g) for 20 hr. The mixture is partitioned between methylene chloride/ether and aqueous sodium bicarbonate, the phases are separated, the organic phase is dried with sodium sulfate and concentrated to give 2-piperazinobenzothiazole which is reacted at 70° in acetonitrile (200 ml) with 21-bromo-17α-hydroxypregna-4,9(11)-diene-3,20-dione (7.45 g) and potassium carbonate (2.44 g) for 6 hr and at 20°-25° for 3 days. The mixture is partitioned between methylene chloride and aqueous sodium bicarbonate, the phases are separated, the organic phase is dried with sodium sulfate and concentrated. The concentrate is chromatographed on silica gel eluting with methanol/methylene chloride (6/94) to give the title compound which is recrystallized from ethyl acetate.

Workup

  1. customThe mixture is partitioned between methylene chloride/ether and aqueous sodium bicarbonate
  2. customthe phases are separated
  3. dry with materialthe organic phase is dried with sodium sulfate
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-61b6f5f6c1104aaa89f720569f018630
Source dataset
uspto-grants-1992_12
Patent number
US05175281

Reaction notes

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