(3R)-3-benzylpiperazine-2,5-dione

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude product D-Phe-Gly-OMe (6 g, 25 mmol) was powdered and then dispersed in 100 ml toluene and heated at reflux overnight. The reaction flask was cooled to 0° C. and the solid product (3.50 9, 69%) was collected by filtration: m.p. 256°-257° C.; DCI-NH3 -MS, m/z (relative intensity), 222 (MNH4+, 100%), 205 (MH+, 31%); heated at reflux overnight the solid product (3.50 9, 69%) was collected by filtration

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude product D-Phe-Gly-OMe (6 g, 25 mmol) was powdered and then dispersed in 100 ml toluene and heated at reflux overnight. The reaction flask was cooled to 0° C. and the solid product (3.50 9, 69%) was collected by filtration: m.p. 256°-257° C.; DCI-NH3 -MS, m/z (relative intensity), 222 (MNH4+, 100%), 205 (MH+, 31%); heated at reflux overnight the solid product (3.50 9, 69%) was collected by filtration

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude product D-Phe-Gly-OMe (6 g, 25 mmol) was powdered and then dispersed in 100 ml toluene and heated at reflux overnight. The reaction flask was cooled to 0° C. and the solid product (3.50 9, 69%) was collected by filtration: m.p. 256°-257° C.; DCI-NH3 -MS, m/z (relative intensity), 222 (MNH4+, 100%), 205 (MH+, 31%); heated at reflux overnight the solid product (3.50 9, 69%) was collected by filtration