Sodium Hydroxide → L-Proline, 1-ethyl-5-oxo-

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Reaction Steps

Methyl 1-ethyl-5-oxo-prolinate (1.91 g, 11.17 mmol) was dissolved in methanol (25 ml) and treated with 2M aqueous sodium hydroxide (7.3 ml, 14.52 mmol). The mixture was stirred for 4 hrs at room temperature and then washed with dichloromethane. The aqueous layer was evaporated and the residue treated with an excess of 1M hydrogen chloride in ether (˜5 ml). The mixture was evaporated once more and the residue was triturated with dichloromethane. The solid material was discarded and the combined dichloromethane fractions were evaporated to give a clear oil which crystallized on standing. Trituration with hexane and ether and drying gave pure 1-ethyl-5-oxo-proline (0.271 g) as a white solid.

Provenance & Evidence