Hydrogen Bromide → 4-keto-L-proline hydrobromide

HRID 1065656Notes

Reaction equation

HRID 1065656 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]>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

4

Reactant 2

HCID 260Hydrogen BromideHCID 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 250 ml. 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. customof ether, triturating the gummy product
  2. customthe resulting tacky solid is triturated with fresh ether and finally with 50 ml

Sources & evidence

ORD record
ord-631b8b5a2a804e03ad2ac65b67342fad
Source dataset
uspto-grants-1982_05
Patent number
US04330548

Reaction notes

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