Reaction conditions
(a) dry Methylene chloride, 0 °C , TEA (reactant ratio: imine/TEA/N-phthaloylglycinyl chloride: 1/6.5/6)
(b) methylene chloride, room temp., sun light
(c) Hydrazine, MeOH, 37 °C, 3 h (reactant ratio: b-lactam/hydrazine: 1/4.5)