Acetic Anhydride → HCID 59880457, compound

HRID 962921Notes

Reaction equation

HRID 962921 reaction equation
[CH3:1][C:2]1[NH:3][C:4]([CH3:26])=[C:5]([C:23]([OH:25])=[O:24])[C@@H:6]([C:14]2[CH:19]=[CH:18][CH:17]=[C:16]([N+:20]([O-:22])=[O:21])[CH:15]=2)[C:7]=1[C:8]([O:10][CH2:11][CH2:12][NH2:13])=[O:9].[C:27](OC(=O)C)(=[O:29])[CH3:28]>O>[C:27]([NH:13][CH2:12][CH2:11][O:10][C:8]([C:7]1[C@H:6]([C:14]2[CH:19]=[CH:18][CH:17]=[C:16]([N+:20]([O-:22])=[O:21])[CH:15]=2)[C:5]([C:23]([OH:25])=[O:24])=[C:4]([CH3:26])[NH:3][C:2]=1[CH3:1])=[O:9])(=[O:29])[CH3:28]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 9928868HCID 9928868, compound

Product 1

HCID 59880457HCID 59880457, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

That is, 10 mg of the (4R)-1,4-dihydro-2,6-dimethyl3-(2-aminoethyl) oxycarbonyl-4-(3-nitrophenyl)pyridine-5-carboxylic acid obtained in Example 28 was dissolved in 2 ml of deionized water and 0.2 ml of acetic anhydride was added to the solution while stirring at room temperature. After stirring for continuous 30 minutes, the reaction mixture was extracted 3 times with 5 ml each of ethyl acetate and washed with 10 ml of saturated saline. The ethyl acetate layer was adsorbed on a preparatory TLC plate, developed with chloroform/methanol (7:1) to elute fractions showing UV absorption at Rf 0.22. The eluate was evaporated to dryness to obtain 3.7 mg of (4R)-3-(2-acetamidoethyl) oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl) pyridine-5-carboxylic acid. The optical purity of this substance was determined by HPLC(mobile phase: 0.35% isopropanol/0.1M phosphaste buffer solution (pH 4.4), flow rate: 0.8 ml/minute) using an otical resolution column: CHIRAL AGP (4 mm×100 mm) manufactured by Daicel Chemical Industries Ltd. As a result, it revealed that the optical purity of the 4R form was 100% and the retention time was 14.3 minutes.

Workup

  1. stirringAfter stirring for continuous 30 minutes
  2. extractionthe reaction mixture was extracted 3 times with 5 ml each of ethyl acetate
  3. washwashed with 10 ml of saturated saline
  4. washto elute fractions
  5. customUV absorption at Rf 0.22
  6. customThe eluate was evaporated to dryness

Sources & evidence

ORD record
ord-ac98ab42a94b4512a21f9cb9599d9a23
Source dataset
uspto-grants-1998_06
Patent number
US05760238

Reaction notes

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