Trifluoroacetic acid → Tetrahydropyridino[1,2-c][1,2,3]oxadiazolone
Reaction equation
[N:1]([N:3]1[CH2:11][CH2:10][CH2:9][CH2:8][CH:4]1[C:5]([OH:7])=[O:6])=O.FC(F)(F)C(O)=O>ClCCl>[NH:1]1[N:3]2[CH2:11][CH2:10][CH2:9][CH2:8][CH:4]2[C:5](=[O:7])[O:6]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
N-Nitrosopipecolinic acid (prepared by the method of W. Lijinsky, L. Keefer and J. Loo Tetrahedron 1970, 26, 5137) (1.82 g, 11.5 mM) ) in dichloromethane (15 ml) was cooled in ice and treated dropwise with trifluoroacetic acid (1.62 ml, 11.5 mM). The mixture was stirred with cooling for 6 h then diluted with further dichloromethane, and washed with saturated aqueous sodium hydrogen carbonate solution until the washings were neutral. The organic phase was dried (MgSO4) and evaporated to give the title compound as a yellow oil (1.12 g, 76%); νmax (CH2Cl2) 1732 cm−1; δH (CDCl3) 1.90-2.02 (2H, m), 2.04-2.19 (2H, m), 2.63 (2H, t, J 6 Hz) and 4.25 (2H, t, J 6 Hz); EI m/e 140 (93%).