(-)-2-amino-1butanol D-(-)-mandelate → (-)-Mandelic acid

HRID 128492

Reaction equation

HRID 128492 reaction equation
[C:1]([O:11]CC(N)CC)(=[O:10])[C@@H:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[OH:3]>O>[C:1]([OH:11])(=[O:10])[C@@H:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[OH:3]

Participants

3

Reactant 1

HCID 70562055(-)-2-amino-1butanol D-(-)-mandelate

Product 1

HCID 11914(-)-Mandelic acidYield 72.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
-5 °C

Procedure

A portion of the (-)-2-amino-1-butanol D-(-)-mandelate wet cake (155 grams "as is"--90.3% pure; 0.58 mole) from resolution A is dissolved in water (125 mls) at 50°-55° C. and the resulting solution is distilled under vacuum to remove 48.5 mls of methanol and water. The concentrated solution is treated with 37% hydrochloric acid (60 mls) and the acidified solution is cooled to -5° C. over about 5 hours to crystallize D-(-)-mandelic acid from the solution. The crystals are isolated by filtration, washed twice with ice cold (0°-5° C.) water (20 mls), twice with hexane (20 mls), and dried at 60° C. to obtain 64.1 grams of D-(-)-mandelic acid (72.6% of theoretical; m.p. 131°-133° C.; [α]D25 =-154.1° (C=2. H2O)).

Workup

  1. distillationthe resulting solution is distilled under vacuum
  2. customto remove 48.5 mls of methanol and water
  3. additionThe concentrated solution is treated with 37% hydrochloric acid (60 mls)
  4. customto crystallize D-(-)-mandelic acid from the solution
  5. customThe crystals are isolated by filtration
  6. washwashed twice with ice cold (0°-5° C.) water (20 mls), twice with hexane (20 mls)
  7. customdried at 60° C.

Sources & evidence

ORD record
ord-132d99b23ce84ba99ad73af6c75c17ee
Source dataset
uspto-grants-1981_03
Patent number
US04259521

Linked notes

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