Hydrogen Bromide → 4-keto-L-proline hydrobromide

HRID 1106086Notes

Reaction equation

HRID 1106086 reaction equation
C([N:11]1[CH2:18][C:17](=[O:19])[CH2:16][C@H:12]1[C:13]([OH:15])=[O:14])(OCC1C=CC=CC=1)=O.[BrH:20].CCOCC>C(O)(=O)C>[BrH:20].[O:19]=[C:17]1[CH2:18][NH:11][C@H:12]([C:13]([OH:15])=[O:14])[CH2:16]1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 3283Diethyl EtherHCID 11076282N-Carbobenzyloxy-4-keto-L-proline

Product 1

HCID 127736614-keto-L-proline hydrobromide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To 4.0 g. (0.015 mole) of N-carbobenzyloxy-4-keto-L-proline are added 20 ml. of hydrogen bromide in acetic acid (30-32%). The mixture is frequently swirled over a period of eight minutes. At the end of this period (effervescence has stopped), the yellow-orange solution is layered over with 25° of ether, triturating the gummy product. The ether is discarded and the resulting tacky solid is triturated with fresh ether and finally with 50 ml. of acetonitrile to give 4-keto-L-proline, hydrobromide as a crystalline solid weighing 2.7 g. (85%), m.p. 153°-155° (dec.,), [α]D26 -49° (c, 1% in water).

Workup

  1. customtriturating the gummy product
  2. customthe resulting tacky solid is triturated with fresh ether and finally with 50 ml

Sources & evidence

ORD record
ord-0fb3fe9b8e1f4a85b14dc7f329554ab2
Source dataset
uspto-grants-1982_01
Patent number
US04311697

Reaction notes

Loading…