五乙二醇单苄醚

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of Compound 19 (2.04 g, 6.21 mmol) in methylene chloride (20 ml), a solution of carbon tetrabromide (4.12 g, 12.4 mmol) in methylene chloride (10 ml) was added at room temperature; after cooling with ice, triphenylphosphine (2.51 g, 12.4 mmol) was added. The water bath was removed, and this was followed by stirring at room temperature for 1 hour. After concentration under reduced pressure, the residue obtained was purified by silica gel column chromatography (Yamazen YFLC Gel, eluent (n-hexane:ethyl acetate 2:1-1:1)) to yield Compound 20 (light-yellow oil 2.14 g, 88%). was added The water bath was removed After concentration under reduced pressure the residue obtained was purified by silica gel column chromatography (Yamazen YFLC Gel, eluent (n-hexane:ethyl acetate 2:1-1:1))

反应条件: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To Compound 1 (5.2 g, 21.8 mmol), potassium hydroxide (1.2 g, 21.4 mmol) was added; this was followed by stirring on an oil bath at 130° C. for 15 minutes, after which the oil bath was removed and benzyl chloride (2.7 g, 21.3 mmol) was gradually added. This was again heated to 130° C. and stirred for 2 hours. After the solution was allowed to cool to room temperature, water was poured to stop the reaction, and extraction from methylene chloride was conducted. The combined organic phases were dried with sodium sulfate, filtered, and concentrated under reduced pressure, after which the residue obtained was purified by silica gel column chromatography (Yamazen YFLC Gel, eluent (ethyl acetate—5% methanol-ethyl acetate solution) to yield Compound 19 (light-yellow oil 2.3 g, 32%). after which the oil bath was removed This was again heated to 130° C. stirred for 2 hours to cool to room temperature The combined organic phases were dried with sodium sulfate filtered concentrated under reduced pressure after which the residue obtained was purified by silica gel column chromatography (Yamazen YFLC Gel, eluent (ethyl acetate—5% methanol-ethyl acetate solution)

反应条件: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Metal sodium (115 mg, 5.0 mmol) was added to pentaethylene glycol monobenzyl ether (328 mg, 1.0 mmol), and the mixture was stirred at 90° C. for three hours. Chloroacetic acid (47 mg, 0.5 mmol) was added to the mixture which was then stirred at 90° C. for 16 hours. Water was added to the mixture which was then washed with ethyl acetate. Next, the aqueous layer was made acidic by 1 N hydrochloric acid, followed by extraction with ethyl acetate. The extract was dried over anhydrous sodium sulfate, and then the solvent was evaporated under reduced pressure to obtain 390 mg of crude [2-(2-{2-[2-(2-benzyloxyethoxy)ethoxy]ethoxy}ethoxy)ethoxy]acetic acid in the form of a reddish brown substance. was then stirred at 90° C. for 16 hours was then washed with ethyl acetate followed by extraction with ethyl acetate The extract was dried over anhydrous sodium sulfate the solvent was evaporated under reduced pressure