Trimethylamine oxide → HCID 19364698, compound

Temperature

0 °C

2.5 ml (25 mmol) of borane-dimethyl sulphide (1:1) complex were dissolved in 50 ml of dimethoxyethane and the solution was cooled to 0° C. under nitrogen. 5.3 ml (52.5 mmol) of cyclohexene were then added. The solution was stirred at 0° C. for 15 minutes, then at room temperature for 1 hour and then cooled to -10° C. 1.6 g (27 mmol) of 3-fluoropropene were condensed and then added to the foregoing solution which was then stirred at room temperature under a dry ice condenser. After 1 hour the condenser was removed and stirring was continued for a further 1 hour. 3.9 g (52 mmol) of trimethylamine N-oxide were added and the solution was stirred for 1 hour. 3.1 g (26.3 mmol) of 2,3-dimethyl-2,3-butanediol were added and the solution was stirred for 16hours. The solution was evaporated and the residue was distilled. The distillate boiling at 35°-65° C./1 mm Hg was collected and purified by chromatography on silica gel using diethyl ether/ hexane (1:9)for the elution to give 1.67 g of 4,4,5,5-tetramethyl-2-(3-fluoropropyl)-1,3,2-dioxaborolane as a colourlessoil; 1H NMR (250 MHz, CDCl3) δ: 0.75-0.85 (m, 2 H), 1.25 (s, 12 H), 1.7-1.9 (m, 2 H), 4.28 (t, 1 H), 4.48 (t, 1 H).

1. waitat room temperature for 1 hour
2. temperaturecooled to -10° C
3. customcondensed
4. additionadded to the foregoing solution which
5. stirringwas then stirred at room temperature under a dry ice condenser
6. customAfter 1 hour the condenser was removed
7. stirringstirring
8. waitwas continued for a further 1 hour
9. stirringthe solution was stirred for 1 hour
10. stirringthe solution was stirred for 16hours
11. customThe solution was evaporated
12. distillationthe residue was distilled
13. distillationThe distillate boiling at 35°-65° C./1 mm Hg was collected
14. custompurified by chromatography on silica gel
15. wash9)for the elution

ORD record

ord-34c0b869e0744f89babee7ae335738cf

Source dataset

uspto-grants-1999_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05866684