Hydrochloric Acid → HCID 21932004, compound

Temperature

-70 °C

Under an Ar atmosphere at 0° C., BuLi (2.5M in hexanes, 80 mL, 0.20 mol) was added dropwise to a solution of iPr2NH (27.2 mL, 194 mmol, distilled from NaOH) in dry THF (200 mL) in 30 min. The reaction mixture was stirred for 30 min, cooled to −70° C. and then, t-butyl cyclopropanecarboxylate (25.0 g, 176 mmol) was added dropwise in 30 min. The resultant mixture was allowed to warm up to −35° C., cooled again to −70° C. and then 1-bromo-5-chloropentane (36 mL, 50.7 g, 273 mmol) was added dropwise in 15 min. The reaction mixture was allowed to reach −5° C., stirred for 3 h, poured into a mixture of ice (100 mL), H2O (100 mL), brine (200 mL) and aqueous HCl (2 M, 200 mL) and extracted with Et2O (2×300 mL). The combined organic layers were washed with a mixture of brine and saturated aqueous NaHCO3 (10:1, 300 mL) and dried. The remaining oil was purified by fractional distillation under reduced pressure to give 104c (31.5 g, 73%) as a colorless liquid. bp: T=67-74° C. (p=0.001 mbar). 1H NMR: 3.52 (t, J=6.6 Hz, 2H), 1.77 (quintet, J=6.8 Hz, 2H), 1.48-1.38 (m, 6H), 1.42 (s, 9H), 1.10 (dd, J=6.5 Hz, 3.8 Hz, 2H), 0.59 (dd, J=6.6, 3.9 Hz, 2H). 13C NMR: δ 174.1, 79.9, 45.2, 34.2, 32.7, 28.2 (3×), 27.20, 27.17, 24.3, 15.4 (2×). HRMS calcd for C13H24ClO2 (MH+): 247.1465, found: 247.1465.

1. temperatureto warm up to −35° C.
2. temperaturecooled again to −70° C.
3. customto reach −5° C.
4. stirringstirred for 3 h
5. extractionextracted with Et2O (2×300 mL)
6. washThe combined organic layers were washed with a mixture of brine and saturated aqueous NaHCO3 (10:1, 300 mL)
7. customdried
8. distillationThe remaining oil was purified by fractional distillation under reduced pressure

ORD record

ord-d2d0c6596a394d9097806567cf183fbc

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07705177B2