Stearyl Methacrylate synthesis

Yield:32360-05-7 99.3 %Chromat.

Reaction Conditions:

Stage #1: 1-octadecanol;methacrylic acid methyl esterwith 4-acetylamino-2,2,6,6-tetramethyl-1-piperidinoxy for 1 h;Heating / reflux;
Stage #2: titanium tetramethoxide at 111 - 129; for 4 h;Product distribution / selectivity;

Steps:

2

Example 2; The same reaction apparatus as used in Example 1 was used. First, the reactor was charged with 750.9 9 (7.5 mol) of methyl methacrylate, 676.3 g (2.5 mol) of stearyl alcohol and 0.042 g of 4-acetylamino-2,2,6,6-tetramethylpiperidine-N-oxyl, and the mixture was then heated to conduct dehydration in the reaction system over a period of 1 hour under the total reflux. Then, the reactor was cooled and charged with 1.23 g (0.005 mol) of tetramethyl titanate (purity: 70%), and heating was begun again. And thereafter, the ester-exchange reaction was carried out in the same manner as in Example 1. At the beginning of the reaction, the operation was conducted under the total reflux, and the removal of an azeotropic mixture of methanol/methyl methacrylate from the reaction system was started at the time when the temperature of the uppermost stage in the distillation column reached 64.5° C., the temperature of the middle stage 74° C., and the temperature of the lowest stage 98.8° C. (the conversion of 4% at this time). Thereafter, until the conversion reached 97%, the reaction was carried out while controlling the reflux ratio within the range of 5 to 50, so as to maintain the temperature of the uppermost stage in the distillation column at 64 to 65° C., the temperature of the middle stage at 70 to 80° C., and the temperature of the lowest stage at 99 to 100° C. After 4 hours from the beginning of the reaction, the conversion reached 98% and the temperature of the middle stage in the distillation column rose to 93° C. Thereafter, in order to completely remove, from the reaction system, methanol contained in the liquid refluxed from the uppermost stage in the distillation column to the uppermost stage in the distillation column again through the condenser and the reflux line, the reflux ratio was set to zero, and thereby all the liquid in the reflux line was distilled off until the temperature of the uppermost stage in the distillation column was stably maintained at 98° C. or higher. Thus, the reaction was terminated. The reaction time was 4.5 hours. During this time, the temperature of the uppermost stage in the distillation column was maintained at 95° C. or higher, and the temperatures of the middle stage and the lowest stage in the distillation column were maintained at 99° C. or higher. The amount of the azeotropic mixture of methanol/methyl methacrylate removed was 124.5 g, and the content of methanol was 62.8% (78.2 g) and the content of methyl methacrylate was 37.2% (46.3 g). When 1297.7 g of the resulting reaction solution in the reactor was analyzed by gas chromatography, it contained 35.0% of methyl methacrylate, 0% of stearyl alcohol and 64.8% of stearyl methacrylate, and the yield was 99.3%.

References:

US2006/84823,2006,A1 Location in patent:Page/Page column 5-6