Hydrochloric Acid → DO2A
Reaction equation
[O:1]=[C:2]1[N:13]2[CH2:14][CH2:15][N:4]([CH2:5][CH2:6][NH:7][CH2:8][CH2:9][N:10]([CH2:16][C:17]([OH:19])=[O:18])[CH2:11][CH2:12]2)[CH2:3]1.Cl.[OH-:21].[Na+]>>[N:10]1([CH2:16][C:17]([OH:19])=[O:18])[CH2:11][CH2:12][NH:13][CH2:14][CH2:15][N:4]([CH2:3][C:2]([OH:21])=[O:1])[CH2:5][CH2:6][NH:7][CH2:8][CH2:9]1Participants
Procedure
20 g (0.074 mol) of 12-oxo-1,4,7,10-tetraazabicyclo[8.2.2]tetradecane-4-acetic acid, prepared as described in example 5, are dissolved in 88.8 g of 10% NaOH. The solution is refluxed overnight, then cooled and acidified to pH 12 by addition of conc. HCl. The resulting solution is percolated on a column containing 600 ml of anionic exchanger resin IRA420 (Rohm & Haas), which is washed repeatedly with water, then eluted with 1N HCl. The fractions containing the product are combined and concentrated at reduced pressure to a volume of about 500 mL. The solution is percolated on a column containing 2 L of polyvinylpyridine resin (PVP), eluting with water, the fractions containing the desalted product are collected, combined and concentrated to dryness under vacuum. The crude solid is recrystallized from methanol/acetone=8/2, finally dried in a static drier at 50° C. under vacuum. 18.5 g (0.064 mol) of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid are obtained.
Workup
- temperatureThe solution is refluxed overnight
- temperaturecooled
- washis washed repeatedly with water
- washeluted with 1N HCl
- additionThe fractions containing the product
- concentrationconcentrated at reduced pressure to a volume of about 500 mL
- additioncontaining 2 L of polyvinylpyridine resin (PVP)
- washeluting with water
- additionthe fractions containing the desalted product
- customare collected
- concentrationconcentrated to dryness under vacuum
- customThe crude solid is recrystallized from methanol/acetone=8/2
- customfinally dried in a static drier at 50° C. under vacuum
Sources & evidence
- ORD record
- ord-9a5a405bd9dc470a84a75bff67f4e636
- Source dataset
- uspto-grants-1999_11
- Patent number
- US05977353
Reaction notes
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