PYRIDO[4,3-D]PYRIMIDINE, 5,6,7,8-TETRAHYDRO-2-PHENYL-, MONOHYDROCHLORIDE synthesis

Yield:300552-48-1 256 mg (>100%)

Reaction Conditions:

with hydrogenchloride in ethyl acetate;

Steps:

101.D Step D:

Step D: 2-Phenyl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine hydrochloride To a solution of 2-phenyl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine-6-carboxylic acid tert-butyl ester (prepared according to the method of Example 101, Step C, 304 mg, 0.98 mmol) in ethyl acetate (2 mL) was added hydrogen chloride (2.5 M in ethyl acetate, 3.9 mL, 9.76 mmol). This mixture was stirred at room temperature for 16 h and concentrated to give 256 mg (>100%) of the title compound of Example 101, Step D as a pale yellow solid. ¹H NMR (CD₃OD, 400 MHz) δ8.75 (s, 1H), 8.42-8.38 (c, 2H), 7.51-7.45 (c, 3H), 4.48 (s, 2H), 3.68 (t, 2H) 3.35-3.25 (buried, 2H); MS (APCI) 212 (MH⁺).

References:

US6414149,2002,B1