Diisopropylamine → HCID 12638302, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of dry diisopropylamine (7.7 ml, 5.5 ×10-2 mol) and dry THF (25 ml) under argon at 0° C. is added dropwise a hexane solution of n-butyl-lithium (21.1 ml, 5.5 ×10-2 mol). After stirring 1/2 hour at 0° C. a solution of t-boc-piperazinone (2) (5.0 g, 2.5 ×10-2 mol) and dry THF (125 ml) is added dropwise. The resultant mixture is stirred at 0° C. for 3 hours before a solution of p-benzyloxybenzyl chloride (6.40 g, 0.75 ×10-2 mol) and dry THF (20 ml) is added dropwise via syringe. This mixture is stirred an additional hour at 0° C. before the cooling bath is removed and the reaction allowed to warm to room temperature. After stirring overnight the mixture is quenched into saturated aqueous NH4Cl. The aqueous phase is extracted with Et2O (3 times) and CH2Cl2 (2 times). The ethereal extracts are combined and subsequently washed with saturated aqueous NaCl as are the CH2Cl2 extracts. The ethereal and CH2Cl2 extracts are then combined and dried over Na2SO4. Filtration of the drying agent and evaporation of the filtrate gives 3a as an almost colorless solid which crystallizes from ethyl acetate as colorless prisms 5.2 g (53%), m.p. 145°-147° C.

Provenance & Evidence