2-Hydroxy-4-(3-triethoxysilylpropoxy)diphenyl ketone → 2,4-Dihydroxybenzophenone

Participants

Reaction Steps

A mixture of 12.495 grams of recrystallized 4-allyloxy-2-hydroxybenzophenone (AHBP), 8.215 grams of triethoxysilane and 0.20 grams of the platinum substituted silica gel of Example 1 was heated at 90° C. It was found that the AHBP melted around 55° C. The reaction mixture became yellow and homogeneous. The temperature of the reaction mixture then quickly rose to 130° C. and then dropped to 90° C. After heating the mixture of an additional hour at about 90° C., the mixture was allowed to cool to 23° C., diluted with 50 ml of hexane and then filtered. The platinum substituted silica gel was recovered as a free-flowing tan powder. The filtrate was concentrated on a rotary evaporator and 20 grams of a yellow oil, a quantitative yield of product was recovered. Based on method of preparation and reverse phase TLC, 4/1;ethanol/water, the product was 4-(3'-triethoxysilylpropoxy)-2-hydroxybenzophenone (SHBP). A trace amownt of 2,4-dihydroxybenzophenone was also obtained. The 1H NMR spectrum of the SHBP was found to be identical to a spectrum of SHBP prepared from AHBP and triethoxysilane using a platinum catalyst shown by Karstedt, U.S. Pat. No. 3,775,452.

Provenance & Evidence