Preparation method of varenicline tartrate intermediate

[0037] Ammonium formate solution: Add 4.4 g of ammonium formate into 9 ml of purified water and stir to dissolve.

[0038] Add 36ml of methanol to the reaction flask. Under the protection of nitrogen, 10% Pd / C 0.5g (dry basis) and the compound of formula II (3g, 8.7mmol) were added successively, and stirred for 5-10 minutes.

[0039] Ammonium formate solution was added dropwise. After dropping, stir at 30°C to 40°C for 40 to 60 minutes.

[0040] TLC detection, after the reaction is complete, add 20ml of dichloromethane to the reaction solution, spread diatomaceous earth to filter, add 30ml of purified water to the filtrate, leave to stand for layering after stirring, extract the aqueous phase twice with dichloromethane, combine the organic phase, dried with 10 g of anhydrous sodium sulfate, filtered, and the filtrate was concentrated to dryness under reduced pressure to obtain 2.25 g, yield: 90.8%, purity: 98.3%, and was directly used for feeding in the next step.

[0042] Ammonium formate solution: Add 4.4 g of ammonium formate into 9 ml of purified water and stir to dissolve.

[0043] Add 36ml of ethanol to the reaction flask. Under the protection of nitrogen, 10% Pd / C 0.5g (dry basis) and the compound of formula II (3g, 8.7mmol) were added successively, and stirred for 5-10 minutes.

[0044] Ammonium formate solution was added dropwise. After dropping, stir at 30°C to 40°C for 40 to 60 minutes.

[0045] TLC detection, after the reaction is complete, add 20ml of dichloromethane to the reaction solution, spread diatomaceous earth to filter, add 30ml of purified water to the filtrate, leave to stand for layering after stirring, extract the aqueous phase twice with dichloromethane, combine the organic phase, dried with 10 g of anhydrous sodium sulfate, filtered, and the filtrate was concentrated to dryness under reduced pressure to obtain 2.23 g, yield: 90.0%, purity: 98.2%, and was directly used for feeding in the next step.

[0047] Ammonium formate solution: Add 4.4 g of ammonium formate into 9 ml of purified water and stir to dissolve.

[0048] Add 36 ml of N-methylpyrrolidone into the reaction flask. Under the protection of nitrogen, 10% Pd / C 0.5g (dry basis) and the compound of formula II (3g, 8.7mmol) were added successively, and stirred for 5-10 minutes.

[0049] Ammonium formate solution was added dropwise. After dropping, stir at 30°C to 40°C for 40 to 60 minutes.

[0050]TLC detection, after the reaction is complete, add 20ml of dichloromethane to the reaction solution, spread diatomaceous earth to filter, add 30ml of purified water to the filtrate, leave to stand for layering after stirring, extract the aqueous phase twice with dichloromethane, combine the organic phase, dried with 10 g of anhydrous sodium sulfate, filtered, and the filtrate was concentrated to dryness under reduced pressure to obtain 2.16 g, yield: 87.1%, purity: 98.6%, and was directly used for feeding in the next step