Tetrabutylammonium Hydroxide → (2S)-3-(3,4-Dihydroxyphenyl)-2-[(tert-butoxycarbonyl)amino]propanoic Acid, Tetrabutylammonium Salt

HRID 229495

Reaction equation

HRID 229495 reaction equation
[C:1]([NH:8][C@@H:9]([CH2:13][C:14]1[CH:21]=[C:19]([OH:20])[C:17]([OH:18])=[CH:16][CH:15]=1)[C:10]([OH:12])=[O:11])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[OH-].[CH2:23]([N+:27]([CH2:36][CH2:37][CH2:38][CH3:39])([CH2:32][CH2:33][CH2:34][CH3:35])[CH2:28][CH2:29][CH2:30][CH3:31])[CH2:24][CH2:25][CH3:26]>CO>[CH2:36]([N+:27]([CH2:23][CH2:24][CH2:25][CH3:26])([CH2:28][CH2:29][CH2:30][CH3:31])[CH2:32][CH2:33][CH2:34][CH3:35])[CH2:37][CH2:38][CH3:39].[OH:20][C:19]1[CH:21]=[C:14]([CH2:13][C@H:9]([NH:8][C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2])[C:10]([O-:12])=[O:11])[CH:15]=[CH:16][C:17]=1[OH:18]

Participants

4

Reactant 2

HCID 2723671Tetrabutylammonium HydroxideHCID 14217229N-(tert-Buloxycarbonyl)-3,4-dihydroxy-L-phenylalanine

Product 1

HCID 46899461(2S)-3-(3,4-Dihydroxyphenyl)-2-[(tert-butoxycarbonyl)amino]propanoic Acid, Tetrabutylammonium SaltYield 83%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
4 °C

Procedure

A solution of N-Boc-(L)-Dopa (175 g, 0.59 mol) in methanol (1 L) was cautiously mixed with a methanolic solution of tetrabutylammonium hydroxide (1.0 M, 0.55 L) at 0° C. for 30 min. The mixture was then concentrated under reduced pressure and dried by azeotroping with toluene twice. The residue was crystallized after cooling at 4° C. for 16 h. The resulting crystalline solid washed with acetone (400 mL×3), collected on a Buchner funnel, and then dried under high vacuum to afford 245 g (83% yield) of the title compound. 1H NMR (400 MHz, DMSO-d6): δ 0.94 (t, J=7.6 Hz, 12H), 1.30 (m, 17H), 1.60 (m, 8H), 3.18 (m, 8H), 4.58 (m, 1H), 5.68 (d, J=5.6 Hz, 1H), 6.30 (d, J=7.6 Hz, 1H), 6.46 (d, J=8.0 Hz, 1H), 6.51 (s, 1H), 8.85 (s, 1H); 8.94 (s, 1H).

Workup

  1. concentrationThe mixture was then concentrated under reduced pressure
  2. customdried
  3. customby azeotroping with toluene twice
  4. customThe residue was crystallized
  5. washThe resulting crystalline solid washed with acetone (400 mL×3)
  6. customcollected on a Buchner funnel
  7. customdried under high vacuum

Sources & evidence

ORD record
ord-2add25ad750b4837a590902a199710ae
Source dataset
uspto-grants-2009_07
Patent number
US07563821B2

Linked notes

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