Diisopropylethylamine → Methyl 4-(guanidinomethyl)benzoate

The mixture of 4-Aminomethyl-benzoic acid methyl ester HCl (15.7 g, 77.8 mmol) in DMF (85.6 mL) and DIPEA (29.5 mL, 171.2 mmol) was stirred at rt for 10 min. Pyrazole-1-carboxamidine HCl (12.55 g, 85.6 mmol) was added to the reaction mixture and then stirred at rt for 4 h to give clear solution. The reaction mixture was evaporated to dryness under vacuum. Saturated NaHCO3 solution (35 mL) was added to give nice suspension. The suspension was filtered and the filter cake was washed with cold water. The mother liquid was evaporated to dryness and then filtered. The two solids were combined and re-suspended over distilled H2O (50 ml). The filter cake was then washed with minimum quantities of cold H2O and ether to give 12.32 g white crystalline solid intermediate 1 (77% yield, M+1: 208 on MS).

1. stirringstirred at rt for 4 h
2. customto give clear solution
3. customThe reaction mixture was evaporated to dryness under vacuum
4. additionSaturated NaHCO3 solution (35 mL) was added
5. customto give nice suspension
6. filtrationThe suspension was filtered
7. washthe filter cake was washed with cold water
8. customThe mother liquid was evaporated to dryness
9. filtrationfiltered
10. distillationover distilled H2O (50 ml)
11. washThe filter cake was then washed with minimum quantities of cold H2O and ether

ORD record

ord-26a467778abc4482abab594c55aaa5e4

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06897220B2