Reaction #71497

Reaction equation

3-bromo-1,1-diethoxy-propan-2-one

N-tert-butoxycarbonylguanidine

→

title compound

Yield 41.7%

2-Amino-4-diethoxymethyl-imidazole-1-carboxylic acid tert-butyl ester

Yield 41.7%

Conditions

Workup

1. 1
   ConcentrationThe reaction mixture was concentrated
2. 2
   workup.ADDITIONdiluted in EtOAc/H2O
3. 3
   Extractionextracted with EtOAc
4. 4
   WashThe organic phase was washed with water and brine
5. 5
   Dryingdried (Na2SO4)
6. 6
   Concentrationconcentrated
7. 7
   OtherThe residue was purified by silica gel column chromatography (DCM/EtOAc, 3:7)

Procedure

A mixture of 3-bromo-1,1-diethoxy-propan-2-one (21.3 g, 95 mmol) (Step 179.9) and N-tert-butoxycarbonylguanidine (45.3 g, 284 mmol, 3 equiv) (Step 179.10) was stirred at 50° C. for 8 h. The reaction mixture was concentrated, diluted in EtOAc/H2O and extracted with EtOAc. The organic phase was washed with water and brine, dried (Na2SO4) and concentrated. The residue was purified by silica gel column chromatography (DCM/EtOAc, 3:7) followed by trituration in Et2O to afford 11.3 g of the title compound as a white solid: ES-MS: 286 [M+H]+; Rf=0.34 (DCM/EtOAc, 3:7).

Source