Alvimopan phenylpropanoic acid methyl ester hydrochloride CAS number is 170098-28-9, it is the last step intermediate of Alvimopan. Molecular formula: C24H31NO3, molecular weight: 418, his synthesis steps is relative longer, the specific operation process is as follows:
1. In a 50L reaction flask, put 1.70Kg of lithium aluminum hydride, 30L of methyl tert-butyl ether, stir to a temperature of 20℃, add 3.5 Kg of benzylmalonate, and dilute with the reaction solvent. The volume of the mixture was stirred at 25℃ for 5 hours after the completion of the dropwise addition. After the reaction was completed, water was slowly added dropwise, and the pH was adjusted to about 3-4 with dilute hydrochloric acid, filtered, and the filtrate was concentrated and then recrystallized from methyl tert-butyl ether to get 2024 g of white crystals.
2. Into a 20 L three-necked flask, 2000 g of white crystals obtained in the step 1, vinyl acetate 5165 g, ethyl acetate 5 L, and Lipas 2650 g were…