Water → Pilocarpic acid ethyl ester

HRID 1648496Notes

Reaction equation

HRID 1648496 reaction equation
[CH2:1](Br)[CH3:2].[CH3:4][CH2:5][C@@H:6]([C:17]([O-:19])=[O:18])[C@H:7]([CH2:15][OH:16])[CH2:8][C:9]1[N:13]([CH3:14])[CH:12]=[N:11][CH:10]=1.[Na+].O>CS(C)=O>[CH3:4][CH2:5][C@H:6]([C:17]([O:19][CH2:1][CH3:2])=[O:18])[C@H:7]([CH2:15][OH:16])[CH2:8][C:9]1[N:13]([CH3:14])[CH:12]=[N:11][CH:10]=1

Participants

5

Reactant 3

HCID 962WaterHCID 6332Ethyl BromideHCID 71749484Isopilocarpic Acid Sodium Salt

Product 1

HCID 15114856Pilocarpic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

9.80 mmoles of ethylbromide (1068 mg) were added dropwise within about an hour to a solution containing 9.80 mmoles (2432 mg) of pilocarpic acid sodium salt in 60 ml of dimethyl sulfoxide. The solution was stirred at room temperature for 48-72 hours and poured into 100 ml of distilled water. The mixture was extracted with two portions of each 150 ml of ethyl acetate. The combined ethyl acetate extracts were washed with 150 ml of distilled water, with 150 ml of 2% sodium bicarbonate solution and with 150 ml of distilled water. The ethyl acetate extracts were dried on calcium sulfate (30 min) and the ethyl acetate evaporated under reduced pressure, and the pilocarpic acid ethyl ester obtained was crystallized from a chloroform/ petroleum ether-mixture, whereby 448 mg (1.76 mmoles) of the ester were obtained.

Workup

  1. extractionThe mixture was extracted with two portions of each 150 ml of ethyl acetate
  2. washThe combined ethyl acetate extracts were washed with 150 ml of distilled water, with 150 ml of 2% sodium bicarbonate solution and with 150 ml of distilled water
  3. dry with materialThe ethyl acetate extracts were dried on calcium sulfate (30 min)
  4. customthe ethyl acetate evaporated under reduced pressure

Sources & evidence

ORD record
ord-b254367ea0f64254986d2fb9aa07a72f
Source dataset
uspto-grants-1995_07
Patent number
US05436350

Reaction notes

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