Tin tetrachloride → HCID 69122097, compound

Participants

Reaction Steps

The nitro compound C5 (59 g, 0.128 mol) was dissolved in methanol (650 mL). Tin chloride (130 g, 0.577 mol, 4.5 eq) was added and the mixture was heated under reflux for 6 hours until completion of the reaction (TLC, 5% methanol in ethyl acetate). The methanol was removed under vacuum and the residue was dissolved in ethyl acetate (1 L) in a 5 L flask and 2 L of saturated sodium hydrogen carbonate aqueous solution was carefully added. The mixture was mechanically stirred for 2 hours and the resulting emulsion was then left to settle overnight. The pH was 8. It was filtered through celite. The residue was washed twice with ethyl acetate and the aqueous layer was extracted with ethyl acetate. The organic layers were combined, dried with magnesium sulfate, and concentrated in vacuo to leave the crude product as a black tar (50 g). TLC analysis showed presence of small quantities of impurities but the product was use in the next step with no further purification. 1H NMR (CDCl3) δ 7.36 (m, 5H), 6.74 (s, 1H), 6.28 (s, 1H), 5.19 (s, 2H), 4.28 (t, J=6.2 Hz, 2H), 3.73 (s, 3H), 3.77-3.50 (m, 2H), 2.91 (t, J=6.2 Hz, 2H), 2.15 (m, 1H), 1.88-1.60 (m, 2H).

Provenance & Evidence