2-Hydroxy-1,2,3-propanetricarboxylic acid hydrate (1:1) → 2-(5-Methyl-2-phenyl-4-oxazolyl)ethanol

Participants

Reaction Steps

A 750-ml 4-necked flask equipped with a mechanical stirrer, a thermometer, a dropping funnel and an argon inlet, cooled with a CO2/acetone bath, was charged with a solution of 49.15 g of crude methyl 2-(5-methyl-2-phenyl-4-oxazolyl)acetate (ca. 0.16 mol) and 90 ml of toluene and stirred. 400 ml of diisobutyl aluminiumhydride 1.2 M in toluene were added under argon at ca. −20 to −25° C. during 60 min. After additional 15 min a solution of 191 g of citric acid monohydrate in 400 ml of deionized water was added with cooling during 30 min, so that the temperature did not exceed 5-10° C. The aqueous phase of the clear biphasic mixture was extracted with 200 ml of toluene. The combined organic phases were washed twice with 40 ml, a total of 80 ml of deionized water, twice with 40 ml, a total of 80 ml of brine and dried (Na2SO4). Rotary evaporation (50° C., 8 mbar, 1 h) afforded 38.5 g of crude 2-(5-Methyl-2-phenyl-4-oxazolyl)ethanol (theor. amount 32.4 g) which was used in the next step without further purification.

Provenance & Evidence