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

HRID 1109925Notes

Reaction equation

HRID 1109925 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-6870f11ca5eb489b85cd746d82026180
Source dataset
uspto-grants-1994_06
Patent number
US05322943

Reaction notes

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