Hydrogen Bromide → Hydrogen Bromide

HRID 325281Notes

Reaction equation

HRID 325281 reaction equation
[BrH:1].C(=O)=O.[CH3:5]COCC.N[C@H](C(N[C:22]1[CH:30]=[CH:29][C:25]([N+]([O-])=O)=[CH:24][CH:23]=1)=O)CCCNC(=N)N>C(O)(=O)C>[CH2:5]([Br:1])[C:22]1[CH:23]=[CH:24][CH:25]=[CH:29][CH:30]=1.[BrH:1]

Participants

7

Reactant 4

HCID 260Hydrogen BromideHCID 280Carbon DioxideHCID 3283Diethyl EtherHCID 178512903HCID 178512903, compound

Product 2

HCID 260Hydrogen BromideHCID 7498Benzyl Bromide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

4.65 g (10 mM) of compound 1a were treated, while stirring, with 40 ml of 2 N HBr in glacial acetic acid for 45 min. at 20° in the absence of moisture. The amino acid derivative dissolved with CO2 evolution. The reaction solution was added dropwise with vigorous stirring to 250 ml of absolute ether which resulted in the precipitation of 2HBr.H-Arg-pNA. The ethereal phase was sucked off, whereupon the solid phase was washed 4 times with portions of 100 ml of abs. ether in order to substantially remove benzyl bromide which had formed as a by-product as well as excess HBr and AcOH. The residue was dissolved in 50 ml of MeOH, the pH was adjusted to 4.5 by the addition of Et3N, and the solution was concentrated to dryness in vacuo at 30°. The resulting product was dissolved in 75 ml of MeOH and passed through a column of "Sephadex" LH-20 (cross-linked dextran gel) equilibrated with MeOH. From a fraction of the eluate there were obtained 4.18 g (91.6% of the theory) of amorphous compound 1b which was homogeneous in the SS as shown by TLC. Elementary analysis and calculation from the empirical formula C12H20N6O3Br2 gave the following values: C=31.15% (31.60%), H=4.35% (4.42%), N=18.84% (18.43%) and Br=34.81% (35.03%).

Workup

  1. additionThe reaction solution was added dropwise
  2. customresulted in the precipitation of 2HBr
  3. washwas washed 4 times with portions of 100 ml of abs

Sources & evidence

ORD record
ord-5b91f1e99eb44fcc9b845aaf7920a8c5
Source dataset
uspto-grants-1984_04
Patent number
US04440678

Reaction notes

Loading…