1,4-Dibromobutane → HCID 14856128, compound

Temperature

-75 °C

To a -75° C. (CO2 /isopropanol bath) mixture of lithium bis(trtmethylsilyl)amide (0.151 mol) and THF (151 mL) under nitrogen was added a 0° C. solution prepared from 14.95 g of a 70:30 mixture between 3-t-butyldimethylsilyl-4-oxothiazolidine and 4-t-butyldimethylsilyloxy-3-thiazoline (prepared as in Example 1) and 1,4-dibromobutane (14.85 g) in THF (50 mL) over a period of 0.5 h. The resultant homogeneous solution was stirred at -75° C. for 70 min. TLC analysis (silica gel, 10% EtOAc/hexane) showed a major product, (Rf =0.48) and a minor product (Rf =0.31). The reaction mixture was removed from the cold bath and acidified with 2N HCl (200 mL). The aqueous mixture was stirred rapidly for 3.5 h at room temperature, placed in vacuo to remove the tetrahydrofuran, and extracted with dichloromethane (5×75 mL). The organic extracts were dried over Na2SO4 and concentrated in vacuo to yield 14.2 g of an oily solid. The crude oily product was chromatographed (Waters Prep 500, 2 silica gel columns, 20% hexane/ethyl acetate) to give 2.75 g of a white solid (Rf =0.45). Recrystallization from diethyletherhexane yielded 1.37 g of a crystalline solid, mp 92°-94° C.

1. additionwas added a 0° C. solution
2. customThe reaction mixture was removed from the cold bath
3. stirringThe aqueous mixture was stirred rapidly for 3.5 h at room temperature
4. customto remove the tetrahydrofuran
5. extractionextracted with dichloromethane (5×75 mL)
6. dry with materialThe organic extracts were dried over Na2SO4
7. concentrationconcentrated in vacuo

ORD record

ord-b81e04be44ca4560a8d7981792273b26

Source dataset

uspto-grants-1994_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05371087