Background and Overview [1] [2]
Lidobutyric acid can be used as an intermediate in pharmaceutical synthesis. If inhaled, please move the patient to fresh air; If skin contact occurs, contaminated clothing should be removed, and the skin should be thoroughly rinsed with soap and water. If there is any discomfort, seek medical attention; If in contact with the sun, the eyelids should be separated, washed with flowing water or physiological saline, and seek medical attention immediately; If swallowed, rinse your mouth immediately, do not induce vomiting, and seek medical attention immediately.
Preparation [3]
The preparation of bile butyric acid is as follows:
1) 1- (p-methoxyphenyl) pyrrolidone -2 (1mol, 204 g), 500ml methanol, 96% sulfuric acid (2mol) were heated to 100 ℃ in an autoclave for 8 hours. After distilling excess methanol, the evaporated residue was dissolved in 1 liter of benzene and neutralized with approximately 300ml of 30% sodium hydroxide (pH=7). After shaking out, separate each phase and extract the benzene solution with 1.4 liters of 1N hydrochloric acid. With the distillation of benzene, 23.8 grams of intermediate 1 were obtained
2) Dissolve 196.1 grams of intermediate 1 in 300ml of benzene and add 70 grams of pyridine. Add para chlorobenzoyl chloride and 250 milliliters of benzene under strong stirring. After about 1 hour, extract the crystallized pyridine hydrochloride, wash thoroughly, and evaporate the benzene to dryness. Dissolve the residue by evaporation and crystallize it from approximately 500ml of cyclohexane to obtain 280 grams of N - (p-chlorobenzoyl) - y - (p-anisidine) methyl butyrate.
3) 280 grams of N - (p-chlorobenzoyl) - y - (p-anisidine) methyl butyrate were dissolved in 1 liter of benzene and treated with 55g of potassium hydroxide solution under strong stirring. Stir the uniform solution at room temperature for 4 hours, then shake with 1 liter of water. With the acidification of the aqueous phase (about pH3), N - (p-chlorobenzoyl) - anisidine butyric acid (cholabutyric acid) was obtained, with a yield of 245 grams and a yield of 91%. The compound melts when recrystallized from acetate at 115-116 ℃.