A mixture of 15.8 g of N-[(2S)-7-hydroxy-1,2,3,4-tetrahydronaphth-2-yl]-(R)-mandelamide, obtained according to Example 3(b), 7.1 ml of ethyl bromoacetate, 22 g of anhydrous potassium carbonate and 1 g of potassium iodide in 600 ml of anhydrous acetone, is heated with reflux and with stirring for 5 hours and a half. The reaction mixture is filtered, evaporated to dryness and the oil which separates is left to crystallize. The solid so obtained is purified by flashchromatography (elution with a 1/1 mixture of ethyl acetate/cyclohexane). The solid on the column is taken up and treated with 20 ml of ethyl ether, filtered and crystallized from ethyl acetate to give 11.5 g of N-[(2S)-7-carbethoxymethoxy-1,2,3,4-tetrahydronaphth-2-yl]-(R)-mandelamide, SR 58638; m.p. 115°-117° C.; [alpha]=-98.3° (methanol, c=1%). Yield: 57%.
