(-)-1,2,3,4-Tetrahydroisoquinoline-3-carboxylic acid

white to light yellow crystal powde

The procedure was adapted from literature. A solution of 1 (phenylalanine) (2.0 g, 12.12 mmol) in HBr (10 mL) was heated to 40 °C. Formaldehyde (1.8 mL, 48.86 mmol) was then added dropwise. The reaction mixture was further heated to 70-80 °C for 3 hours (hrs), during which a white precipitate formed. The reaction was cooled the precipitate was filtered under vacuum and washed with cold ethanol. The white solid product was left under vacuum to dry. Yield = 89percent (1.78 g), Melting Point = 295-300 °C (decomposes); To the suspension of 5.0 g (0.03 mmol) of L-Phe in 50 mL of chloroform and 27 ml of formaldehyde, 45 mL of concentrated hydrochloric acid was added drop-wise. The reaction mixture was stirred at 80-90 °C for 10 h, and TLC (CHClthe suspension of 5.0 g (0.03 mmol) of l-Phe in 50 ml of chloroform and 27 ml of formaldehyde 45 ml of concentrated hydrochloric acid was added drop-wise. The reaction mixture was stirred at 80-90 °C for 10 h, and TLC (CHClA solution of HCl (320 ml)And HCHO (160 ml)Placed in 500ml eggplant bottle, After mixing, L-Phe (30.10 g, 182.45 mmol) was added, The reaction was terminated after reaction at 95 ° C for 24 h in an oil bath, Cool to room temperature.Ice bath with saturated NaOH to adjust the pH to 6 ~ 7, a large number of white solid precipitation.The white solid was filtered(21.80 g, 67.54percent).

Quinapril intermediate.

Molecular Weight:177.20
XLogP3:-1.3
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:177.078978594
Monoisotopic Mass:177.078978594
Topological Polar Surface Area:49.3
Heavy Atom Count:13
Complexity:205
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes