Pentane → tert-Butyl 4-Methoxy-2-(trimethylstannyl)carbanilate

Temperature

-20 °C

A solution of t-butyllithium in pentane (1.70M, 148 mL, 251 mmol, 2.50 equiv) was added via cannula to a solution of tert-butyl 4-methoxycarbanilate (22.4 g, 100 mmol, 1 equiv) in ether (500 mL) at -20° C., producing a cloudy yellow solution. After stirring at -20° C. for 5 h, the reaction mixture was cooled to -78° C. and a solution of trimethyltin chloride (50.0 g, 251 mmol, 2.50 equiv) in ether (50 mL) was added via cannula. After the addition, the reaction mixture was warmed to -20° C. and was stirred at that temperature for 30 min, then was stirred in an ice bath for 30 min. The product solution was partitioned between aqueous phosphate buffer solution (pH 7, 0.05M in sodium hydrogen phosphate and 0.05M in potassium dihydrogen phosphate, 600 mL) and ether (400 mL). The aqueous layer was separated and further extracted with ether (2×400 mL). The combined organic layers were dried over sodium sulfate and were concentrated. The product was purified by flash column chromatography (15% ethyl acetate-hexanes) to afford tert-butyl 4-methoxy-2-(trimethylstannyl)carbanilate (7) as a yellow oil (33.3 g, 85%). ##STR19##

1. customproducing a cloudy yellow solution
2. temperaturethe reaction mixture was cooled to -78° C.
3. additionAfter the addition
4. temperaturethe reaction mixture was warmed to -20° C.
5. stirringwas stirred at that temperature for 30 min
6. stirringwas stirred in an ice bath for 30 min
7. customThe product solution was partitioned between aqueous phosphate buffer solution (pH 7, 0.05M in sodium hydrogen phosphate and 0.05M in potassium dihydrogen phosphate, 600 mL) and ether (400 mL)
8. customThe aqueous layer was separated
9. extractionfurther extracted with ether (2×400 mL)
10. dry with materialThe combined organic layers were dried over sodium sulfate
11. concentrationwere concentrated
12. customThe product was purified by flash column chromatography (15% ethyl acetate-hexanes)

ORD record

ord-1c617a6524e8444cada4ace92f30e0c2

Source dataset

uspto-grants-1998_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05763451