tert-Butyldimethylsilyl chloride → HCID 18761619, compound

Participants

Reaction Steps

A solution of Z-Hyp-OH (1, 300 g, 1.13 mol), TEA (395 mL, 2.83 mol), and DBU (17.2 g, 1.13 mol) in DMF (1.25 L) was stirred in a cold water bath while a suspension of TBS-Cl (188 g, 1.24 mol) in DMF (270 mL) was added slowly at 21-26° C. [Note: moderately exothermic]. The resulting thin suspension was stirred for 22 h at ambient temperature. The reaction mixture was cooled to 2° C. and quenched with water (1.54 L) at ≦26° C. [Note: the pH of the aqueous layer was 8.5-9.0]. MTBE (3 L) was added and the mixture was acidified to pH 3-4 with conc. HCl (168 g) at 17-19° C. The organic layer was separated and washed with water (2×1.5 L). The organic layer was concentrated in vacuo and dried by additional MTBE distillation. Toluene (2×500 mL) was added and distilled to remove moisture to provide 603 g of 2 as a light yellow-colored oil [Note: the water content by KF analysis was 508 ppm]. Based on drying a small sample of 2 to a solid, the contained weight of 2 was 412 g (96% yield, not corrected for purity). 1H NMR (300 MHz, CDCl3): δ7.34 (m, 3H), 7.29 (m, 2H), 5.24-5.11 (m, 2H), 4.52 (m, 1H), 4.43 (m, 1H), 3.64-3.42 (m, 2H), 2.27-2.09 (m, 2H), 0.85 (s, 9H), 0.06 (s, 3H), 0.04 (s, 3H) ppm; 13C NMR (75 MHz, d6-DMSO), mixture of rotomers: δ178.7, 178.4, 159.3, 158.9, 141.9, 141.8, 133.4, 133.3, 132.8, 132.6, 132.3, 131.9, 75.3, 74.6, 71.0, 71.0, 62.8, 62.3, 60.1, 59.7, 44.4, 43.4, 30.6, 30.6, 22.6, 22.6, 0.1, 0.0 ppm. Mass spectrum (ESI), m/z 379.5 [(M)+; calcd for C19H29NO5Si: 379.5].

Provenance & Evidence