Hydrochloric Acid → N-(tetrahydro-2H-pyran-4-yl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-2-amine

A round-bottom flask was charged with 26 (27.5 g, 82.2 mmol), DCM (100 mL) and MeOH (25 mL) and maintained under nitrogen. A 4N solution of HCl in dioxane (103 mL, 411 mmol) was added and the resulting solution stirred for 18 h. The reaction mixture was concentrated and re-suspended in DCM (150 mL). A methanolic NH3 solution (25 mL, 7 N) and additional DCM (100 mL) was added. The precipitated salts were filtered and the filtrate concentrated to afford a brown solid which was stirred with Et2O/MeOH (95:5) for 1 h. A fine light brown solid precipitated and recovered by filtration to afford 15 g, (99% purity, 77% yield) of N-(tetrahydro-2H-pyran-4-yl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-2-amine (28): MS m/z (APCI-pos) M+1=235.2.

1. temperaturemaintained under nitrogen
2. concentrationThe reaction mixture was concentrated
3. additionA methanolic NH3 solution (25 mL, 7 N) and additional DCM (100 mL) was added
4. filtrationThe precipitated salts were filtered
5. concentrationthe filtrate concentrated
6. customto afford a brown solid which
7. customA fine light brown solid precipitated
8. filtrationrecovered by filtration

ORD record

ord-b97c92348d5f41d48752b8477de8241e

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09133187B2