Hydrochloric Acid → Methyl 4-(4-fluorobenzyl)-3-methoxycarbonylbenzoate

A 2.0M solution of 4-fluorobenzyl zinc bromide in tetrahydrofuran (95 ml, 190 mmol; Negishi, E-i. and King, A. O., J.O.C.1977,42,1821) was added dropwise over 20 minutes to a stirred solution of dimethyl 4-bromoisophthalate (20.0 g, 73.2 mmol) and tris(dibenzylideneacetone)dipalladium (0) (0.67 g, 0.73 mmol) in tetrahydrofuran (270 ml) at ambient temperature under an inert atmosphere. During the addition the internal temperature rose to 40° C. The reaction mixture was stirred for 3 hours and then poured into 2M. HCl (1500 ml) cooled in an ice bath and the product extracted into ethyl acetate (3×700 ml). The extracts were washed with water (500 ml), brine (500 ml), dried, and the solvent evaporated under reduced pressure. The residue was taken up in a small quantity of dichloromethane, isohexane added, and the solid, which crystallised from the solution, filtered and dried to give methyl 4-(4-fluorobenzyl)-3-methoxycarbonylbenzoate (10.5 g)

1. additionDuring the addition the internal temperature
2. customrose to 40° C
3. additionpoured into 2M
4. extractionthe product extracted into ethyl acetate (3×700 ml)
5. washThe extracts were washed with water (500 ml), brine (500 ml)
6. customdried
7. customthe solvent evaporated under reduced pressure
8. additionadded
9. customthe solid, which crystallised from the solution
10. filtrationfiltered
11. customdried

ORD-Eintrag

ord-bed6837e3a48416f80e72a5154b0f51e

Quelldatensatz

uspto-grants-2002_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06342765B1