Nitrogen → 12,12-Diethoxydodec-1-yne

Participants

Reaction Conditions

Reaction Steps

To a dark solution of lithium acetylide, ethylenediamine complex (13.8 g, 134.90 mMol, (90%) Su: Aldrich) and NaI (0.78 g, 5.19 mMol, (99+%), Su: Acros) in DMSO (100 ml anhydrous (99.7%) Su: Acros) was charged 10-chloro-1,1-diethoxydecane 3 (27.48 g, 103.77 mMol Su: from step B) while maintaining reaction temperature around 30° C., under a blanket of N2. The addition funnel was rinsed with DMSO (15 ml, anhydrous, Su: Acros). The solution was monitored by GC for compound 3 consumption (compound 3<2.0 Area % by GC). After 4 hr stirring at 30° C., H2O (200 ml) were charged into the reaction mixture to quench the reaction. The aqueous layer was extracted with heptane (2×200 ml). The organic layer was filtered through a plug of Celite® 521 (15 g, Su: Sigma-Aldrich) one by one after phase separation. The combined filtrate was washed with a solution of H2O (100 ml) and brine (50 ml). The water in this organic solution was removed by azeotropic distillation under normal conditions by means of adding and removing heptane (repeat if necessary until KF=˜0.2%). The resultant solution was concentrated under reduced pressure (pot temperature ˜35° C.) to give 24.6 g of 12,12-diethoxydodec-1-yne 4 as an amber liquid (93% yield over steps A thru C, after C). This material was used without further purification. GC: column SP, Rt: 12.2 for 10-chloro-1,1-diethoxydecane 3, and Rt: 11.1 min for 12,12-diethoxydodec-1-yne 4 (<5 Area %). 1H NMR (CDCl3, 400 MHz): δ 4.48 (t, J=5.60, 1H), 3.6 (m, J=7.07 Hz, 2H), 3.5 (m, J=7.07 Hz, 2H), 2.18 (dt, J=7.10, 2.80 Hz, 2H), 1.94 (t, J=2.60 Hz, 1H), 1.6 (m, 2H), 1.52 (qn, J=7.2 Hz, 2H), 1.4 (m, 2H), 1.29 (br s, 10H), 1.20 (t, J=7.00 Hz, 6H).

Provenance & Evidence