3-Chloro-2-chloromethyl-1-propene → Benzyl tert-butyl 4-methylidenepyrazolidine-1,2-dicarboxylate

Participants

Reaction Steps

To a suspension of NaH (3.81 g, 95.4 mmol) in DMF (80 mL) is add dropwise a solution of N-Cbz-N′-Boc-hydrazine (12.1 g, 45.4 mmol) in DMF (20 mL). The reaction mixture is stirred about 20 minutes and 3-chloro-2-chloromethyl-propene (5.8 mL, 50 mmol) is added dropwise and the reaction is allowed to stir at room temperature until the reaction is complete by TLC, approximately 12 hours. The reaction solution is partitioned between ethyl acetate and water, the water layer being extracted several times more with solvent. The combined organic layers are dried, filtered, and concentrated to afford the desired product as a clear oil which is used without further purification.

Provenance & Evidence