反应详情

To a suspension of the product obtained in Step C (1.40 g, 3.91 mmol) in 20 ml of CH2Cl2 there are added 2 drops of DMF and then, dropwise, 684 μl (7.81 mmol) of oxalyl chloride diluted with 2 ml of CH2Cl2. Stirring is carried out at ambient temperature for 2 hours 30 minutes; evaporation to dryness is carried out; the residue is taken up in 15 ml of CH2Cl2; 1.1 ml (7.81 mmol) of Et3N and then 2.94 ml (5.87 mmol) of a 2M solution of dimethylamine in THF are added. Stirring is carried out at ambient temperature for 1 hour. The reaction mixture is acidified with 0.5N HCl and extracted (CH2Cl2). The organic phases are combined, washed (saturated NaCl), dried (MgSO4) and evaporated. The residue is triturated in Et2O; the title product precipitates out and is recovered by filtration. Elemental micro-analysis:

1. customevaporation to dryness
2. stirringStirring
3. waitis carried out at ambient temperature for 1 hour
4. extractionextracted (CH2Cl2)
5. washwashed (saturated NaCl)
6. dry with materialdried (MgSO4)
7. customevaporated
8. customThe residue is triturated in Et2O
9. customthe title product precipitates out
10. filtrationis recovered by filtration