Amino-thienopyrimidine Series

 

Mnr: mnr121-130

Starting material from commercially purchased 4-chloroethieno[3,2-d]pyrimidine

As for Nucleophilic Displacement of MNR99 with Morpholine to give MNR100-1 and Nucleophilic Displacement of MNR99 with Dimethylamine to give MNR122-1

 

 

Hazard Assessment

Procedure

To 4-chloroethieno[3,2-d]pyrimidine (1.0 g, 5.86 mmol) in THF (7 mL) (ethanol (5 mL added to get the starting material into solution) was added ethyl 1-piperazinecarboxylate (1.72 mL, 11.72 mmol at 0 C.  Stirring was contiued overnight (due to having other things on).  In the morning the mixture was washed with HCl (1M), (10 mL) and extracted with EtOAc (4 x 15 mL).  The organic fractions was combined, dried, filtered and concentrated to give the crude as an orange oil (0.107 g).  The aqueous fraction was then concentrated.

 

Thinking that there was a solubiltiy probelm with the product the aqueous layer was concentrated to give a yellow solid.  1H NMR of this showed product and the excess piperazine. All the material was then washed with sodium hydrogen carbonate solution (30 mL) and extraced with EtOAc (40 ml x 3).  The organic fractions were combined, dried, filtered and concentrated to yeild (1.679 g, as a pale yellow solid.   1H NMR showed that the crude still contained 25% ethyl 1-piperazinecarboxylate.  Therefore product = (1.421 g, 4.86 mmol, 83%)

NMR

 - 1H NMR crude HCl extraction

 - 1H NMR or organic layer after making pH12

Conclusion

If repeating this reaction the reaction mixture should just be washed with sodium hydrogen carbonate solution and extracted.  Probelms arrose by making the HCl salt by mistake.