Water → HCID 54007512, compound

HRID 2247793Notes

Reaction equation

HRID 2247793 reaction equation
O.P([O-])([O-])([O-])=O.[CH2:7]([O:9][C:10]([CH:12]1[CH2:17][CH2:16][C:15]2[CH:18]=[CH:19][C:20]([OH:22])=[CH:21][C:14]=2[O:13]1)=[O:11])[CH3:8].[OH-].[Na+]>O1CCCC1>[OH:22][C:20]1[CH:19]=[CH:18][C:15]2[CH2:16][CH2:17][C@H:12]([C:10]([O:9][CH2:7][CH3:8])=[O:11])[O:13][C:14]=2[CH:21]=1

Participants

6

Reactant 4

HCID 962WaterHCID 1061PhosphateHCID 14798Sodium Hydroxide2×HCID 11085381Ethyl 7-hydroxychromane-2-carboxylate

Product 1

HCID 54007512HCID 54007512, compoundYield 35.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A 5 L three-necked flask equipped with a mechanical stirrer, a pH electrode connected to a pH control unit and an addition tube connected to a peristaltic pump, was charged with 2.73 L of deionized water, 682 mL of 0.05M phosphate buffer (pH 7.0) and a solution of 100.0 g (0.45 mol) of racemic-3,4-dihydro-7-hydroxy-2H-1-benzopyran-2-carboxylic acid ethyl ester in 340 mL of tetrahydrofuran. The pH was adjusted to 8 with adequate 1.0N aqueous sodium hydroxide solution, and 9.0 g of Pseudomonas lipase enzyme (P-30, Amano International) was added to the mixture. The hydrolysis was allowed to proceed while stirring at a fast rate and keeping the pH at 8 by adding adequate 1.0N aqueous sodium hydroxide solution via the pump. The hydrolysis was stopped when 40% of the base has been consumed. The tetrahydrofuran in the reaction mixture was removed at 40° C. (10 mm Hg of vacuum) and the aqueous phase was extracted 3×1.0 L=3.0 L of ethyl acetate. The combined organic extracts were washed successively with 500 mL of saturated aqueous sodium bicarbonate solution and 500 mL of brine, then dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the solvent was removed at 35° C. (10 mm Hg) to give 35.1 g (35% yield; 86% of theory) of (R)-3,4-dihydro-7-hydroxy-2H-1-benzopyran-2-carboxylic acid, ethyl ester as a beige solid, m.p. 77°-78° C.; (α)D22 -18.8° (c 1.0, CHCl3); 93.5% e.e.

Workup

  1. customA 5 L three-necked flask equipped with a mechanical stirrer
  2. additionwas added to the mixture
  3. customhas been consumed
  4. customThe tetrahydrofuran in the reaction mixture was removed at 40° C. (10 mm Hg of vacuum)
  5. extractionthe aqueous phase was extracted 3×1.0 L=3.0 L of ethyl acetate
  6. washThe combined organic extracts were washed successively with 500 mL of saturated aqueous sodium bicarbonate solution and 500 mL of brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. customThe drying agent was removed by filtration
  9. customthe solvent was removed at 35° C. (10 mm Hg)

Sources & evidence

ORD record
ord-fcee8f44bbf54991a7a78dca4c15a80c
Source dataset
uspto-grants-1991_08
Patent number
US05037747

Reaction notes

Loading…