Sulfamic Acid → 2-[4-(tert-Butoxycarbonyl)piperazin-1-yl]benzoic acid

HRID 1810954Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[CH:20]=[O:21])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].S(=O)(=O)([OH:24])N.[O-]Cl=O.[Na+]>O1CCOCC1.O.[Cl-].[Na+].O>[C:1]([O:5][C:6]([N:8]1[CH2:9][CH2:10][N:11]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[C:20]([OH:24])=[O:21])[CH2:12][CH2:13]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

Conditions

Temperature: 4 °C

Procedure

An alternative method for preparing this intermediate is as follows. 4-(2-Formyl-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (0.50 g, 1.72 mmol) is dissolved in 80 mL of dioxane and 20 mL of H2O. The mixture is cooled to 4° C. To this is added sulfamic acid (1.36 g, 14.00 mmol) in one portion. The mixture is stirred for an additional 30 min. To this is added 3 mL of a solution of NaClO2 (0.343 g, 3.80 mmol) in a dropwise manner. The reaction is quenched reaction with addition of 50 mL of H2O and 50 mL of brine. The mixture is extracted with 3×100 mL of CH2Cl2. The organic phase is washed with 2×50 mL of brine, dried (MgSO4), filtered and concentrated to give 500 mg of 4-(2-carboxy-phenyl)-piperazine-1-carboxylic acid tert-butyl ester, 95% yield.

Workup

customAn alternative method for preparing this intermediate
customThe reaction is quenched
customreaction
extractionThe mixture is extracted with 3×100 mL of CH2Cl2
washThe organic phase is washed with 2×50 mL of brine
dry with materialdried (MgSO4)
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-8c53e6a1231c436da251af744c1ac6d9
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08362249B2

Reaction notes

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