(2Z)-1-(1,1-Dimethylethyl)-2-butenedioic Acid 4-Methyl Ester synthesis

Yield:55556-65-5 66%

Reaction Conditions:

with sulfuric acid in di-isopropyl ether;toluene at 40; under 760.051 Torr; for 4 h;

Steps:

8

General procedure: A 200 mL four-necked flask was charged with maleic acid (16.3 g, 140 mmol), toluene (10 mL)Diisopropyl ether (30 mL),Sulfuric acid (0.18 mL) was added, and while maintaining the reaction suspension at 30 ° C.,Normal pressure bubbling of isobutene was carried out for 4 hours.An excess amount of isobutene was discharged to the outside of the flask through a paraffin bubbler. The reaction mixture was washed with a saturated aqueous sodium hydrogen carbonate solution (50 mL × 3 times) and saturated brine (50 mL), dried over magnesium sulfate and the solvent was distilled off under reduced pressure to give maleic acid Di (tert-butyl) ester (23.0 g, 100.8 mmol, yield 72%). The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was changed from 30 ° C. to 40 ° C. As a result, di (tert-butyl) maleate maleate (24.1 g, 105.6 mmol, yield 75%).The reaction was carried out in the same manner as in Example 1 except that maleic acid mono (methyl) ester (18.2 g, 140 mmol) was used in place of maleic acid to give maleic acid (methyl) (tert- Butyl) diester (17.2 g, 92.4 mmol, yield 66%).The reaction was carried out in the same manner as in Example 1 except that maleic acid mono (methyl) ester (18.2 g, 140 mmol) was used in place of maleic acid to give maleic acid (methyl) (tert- Butyl) diester (17.2 g, 92.4 mmol, yield 66%).

References:

JP5754133,2015,B2 Location in patent:Paragraph 0063; 0065; 0070