1,1-Dichloroethane → Benzyl 4-(2-(tert-butyldimethylsilyloxy)ethyl)piperazine-1-carboxylate

Participants

Reaction Steps

A mixture of benzyl 1-piperazinecarboxylate (1.751 mL, 9.08 mmol) and 2-(tert-butyldimethylsilyloxy)acetaldehyde (1.209 mL, 9.99 mmol), in MeOH (5 mL) and dichloroethane (5 mL) was stirred for 20 minutes with 4 Å molecular sieves. The mixture was added to a solution of sodium triacetoxyborohydride (4.81 g, 22.70 mmol) in tetrahydrofuran (5 mL) and stirred overnight. The reaction mixture was added to sodium bicarbonate (100 mL) and extracted with CH2Cl2 (3×50 mL). The combined organic extracts were concentrated under reduced pressure, and the residue purified with silica chromatography (EtOAc/MeOH) to give 2.10 g, (61%) of a clear oil. 1H NMR: 7.34 (m, 5H), 5.05 (s, 2H), 3.67 (t, 2H), 3.36 (m, 4H), 2.40 (m, 6H), 0.84 (s, 9H), 0.02 (s, 6H).

Provenance & Evidence