Reaction #62745

Reaction equation

Guanidine hydrochloride

sodium methoxide

guanidine

3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)-2-methoxymethylpropenenitrile

→

yellow solid

Yield 42.8%

2,4-Diamino-5-(7,8-dimethoxy-2H-1-benzopyran-5-ylmethyl)pyrimidine

Yield 42.8%

Solvents

methanol

methanol

Conditions

Workup

1. 1
   Filtrationthe resultant sodium chloride was filtered
2. 2
   Washwashed with methanol (10 mL)
3. 3
   Temperaturethe mixture heated
4. 4
   Temperatureat reflux for 2 hr

Procedure

Guanidine hydrochloride (11.46 g, 0.12 mole) in methanol (25 mL) was added to sodium methoxide (6.55 g, 0.12 mole) in methanol (40 mL) and the resultant sodium chloride was filtered and washed with methanol (10 mL). The guanidine solution was added to 3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)-2-methoxymethylpropenenitrile (11.5 g, 0.04 mole) and the mixture heated at reflux for 2 hr. Cooling the mixture at 3° C. provided 5.38 g of yellow solid in two crops. HPLC assayed yield of 28.6%. A sample recrystallized from alcohol/water gave mp 232°-4° C.

Source