Tetramethyltin → HCID 70357078, compound

Temperature

-50 °C

To boron tribromide (40 ml of a 1.0M solution in methylene chloride) cooled under a nitrogen atmosphere to -50° C. was added dropwise over 1/2 hour tetramethyl tin (7.15 g, 0.04 mol). The resulting solution was stirred for 1/2 hour at -50° C. and then for 1/2 hour at 15° C. The solution was cooled to -78° C. and 4-[1-(methoxyethoxymethoxy)ethyl]-5-methylthiothiophene-2-sulfonamide (3.41 g, 0.01 mol) in methylene chloride (15 ml) was added dropwise over 15 minutes. The mixture was stirred at -78° C. for 3/4 hour and then poured into saturated NaHCO3 solution. Some additional solid NaHCO3 was added and the basic mixture was filtered. The filtrate was extracted with ethyl acetate (2×100 ml). The ethyl acetate solution was extracted with 0.5M KOH solution (2×100 ml). The KOH extracts were washed with ether and acidified with 6N HCl. The acidified mixture was extracted with ethyl acetate (2×50 ml). This extract was washed with saturated NaHCO3, water, dried over anhydrous Na2SO4, filtered and concentrated in vacuo at ambient temperature. A pale amber oil was obtained (1.5 g). NMR confirmed the structure. After trituration in n-butyl chloride the oil solidified. Recrystallization from 1,2-dichloroethane gave 0.54 g (21%) of white solid, m.p. 100-102° C.

1. waitfor 1/2 hour at 15° C
2. temperatureThe solution was cooled to -78° C.
3. stirringThe mixture was stirred at -78° C. for 3/4 hour
4. filtrationthe basic mixture was filtered
5. extractionThe filtrate was extracted with ethyl acetate (2×100 ml)
6. extractionThe ethyl acetate solution was extracted with 0.5M KOH solution (2×100 ml)
7. washThe KOH extracts were washed with ether
8. extractionThe acidified mixture was extracted with ethyl acetate (2×50 ml)
9. washThis extract was washed with saturated NaHCO3, water
10. dry with materialdried over anhydrous Na2SO4
11. filtrationfiltered
12. concentrationconcentrated in vacuo at ambient temperature
13. customA pale amber oil was obtained (1.5 g)
14. customRecrystallization from 1,2-dichloroethane

ORD record

ord-84e58b3217244026bc24566f418301f0

Source dataset

uspto-grants-1990_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04929637