Carbon Dioxide → HCID 88292580, compound

Temperature

-78 °C

A solution of 12.7 g of the title compound of Step B in 300 mL of tetrahydrofuran under a nitrogen atmosphere was cooled to -78° C. To this solution was slowly added 19.2 mL of a 2.5M solution of n-butyllithium in hexane (purchased from Aldrich Chemical Co.). The reaction mixture was maintained below -60° C. during the addition of n-butyllithium and stirring 30 min after addition was complete. The mixture was then cooled to -78° C. and 35.0 g of crushed dry ice was added. The resulting mixture was stirred and allowed to warm to room over 1.5 h. The mixture was then concentrated under reduced pressure, and to the resulting residue was added 300 mL of water. The mixture was then cooled to 0° C., acidified to pH 2 with concentrated hydrochloric acid, and extracted with ethyl acetate. The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure. The resulting solid was crystallized from 1-chlorobutane to gave 3.2 g of the title compound of Step C as a white solid melting at 215° C. (dec.). 1H NMR ((CD3)2SO): δ 1.90 (m, 2H), 2.16 (s, 3H), 2.34 (m, 2H), 2.61 (t, 2H), 2.75 (s, 3H), 3.40-3.70 (m, 4H), 7.29 (s, 1H), 12.75 (br s, 1 H).

1. additionafter addition
2. stirringThe resulting mixture was stirred
3. temperatureto warm to room over 1.5 h
4. concentrationThe mixture was then concentrated under reduced pressure
5. additionto the resulting residue was added 300 mL of water
6. temperatureThe mixture was then cooled to 0° C.
7. extractionextracted with ethyl acetate
8. dry with materialThe combined organic layers were dried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe resulting solid was crystallized from 1-chlorobutane

ORD record

ord-17406cebe3d04af5b6e8d5128f599f91

Source dataset

uspto-grants-1999_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05885936