Triethylene glycol bis(2-ethylhexanoate) synthesis

Yield:94-28-0 97%

Reaction Conditions:

with titanium(IV) isopropylate at 220; under 225.023 - 450.045 Torr; for 3 h;Reagent/catalyst;Pressure;Time;Concentration;pH-value;

Steps:

1 Example 1

Examples 1-5 Preparation of triethylene glycol di-2-ethylhexanoate (3G8 Ester) (0062) A heatable 2 l four-neck flask provided with stirrer, internal thermometer and water separator was initially charged with triethylene glycol and 2-ethylhexanoic acid in a 30 mol % excess, based on the hydroxyl group to be esterified, and 0.045 mol % of tetraisopropyl orthotitanate, based on triethylene glycol, and 1% by weight of activated carbon of the Nuchar RGC type from Mead Westvaco, based on the overall reaction mixture, was added. While stirring and with application of a reduced pressure down to 600 hPa, the mixture was heated to 220° C. and water of reaction formed was removed on the water separator. After a reaction time of 1 hour at this level, the pressure was lowered to 400 hPa and the temperature was left at 220° C. After a further 3 hours of reaction time, the pressure was reduced further to 300 hPa. The course of the reaction was monitored by continuous weighing of the water of reaction discharged via the water separator, and by sampling and gas chromatography analysis of the samples. In the event of a content determined by gas chromatography (% by weight) of triethylene glycol di-2-ethylhexanoate of at least 97% and in the event of a residual hydroxyl number of not more than 5.0 mg KOH/g (DIN 53240), the reaction was ended. The pure esterification time beginning with the first occurrence of water was 8 hours. This was followed by distillative removal of the excess 2-ethylhexanoic acid at 180° C. and 2 hPa down to a residual acid content in the crude ester of 0.18 mg KOH/g (DIN EN ISO 2114/ASTM D 1613) and a Hazen colour number (DIN EN ISO 6271) of 239. (0063) After the residual acid removal had ended, the titanium content in the crude ester was determined to be 18 ppm of titanium. According to Table 1, activated carbon was additionally added in an amount of 0.36% by weight, based on the total mass of the crude ester, and aftertreatment was effected at 90° C. while stirring. The titanium content in the crude ester was determined over the treatment time to ASTM D 5185.

References:

US2015/344400,2015,A1 Location in patent:Paragraph 0062-0063