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

HRID 1023751

Reaction equation

HRID 1023751 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 twice with toluene. The residue was crystallized after cooling at 4° C. for 16 h. The resulting crystalline solid was 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 1a. 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 twice with toluene
  4. customThe residue was crystallized
  5. washThe resulting crystalline solid was washed with acetone (400 mL×3)
  6. customcollected on a Buchner funnel
  7. customdried under high vacuum

Sources & evidence

ORD record
ord-44ddc53140ba4c0882702e44ff0b6b14
Source dataset
uspto-grants-2014_05
Patent number
US08722733B2

Linked notes

Loading…