Water → (E)-3-(2,5-Dibromothiophene-3-yl)acrylic acid methyl ester

To 2,5-Dibromothiophene (1.5 g, 6.2 mmol in THF (30 mL) cooled to −78° C. was added lithium diisopropylamide (6.2 mL, 6.2 mmol; 1.0M in THF, 6.2 mmol;) dropwise. The mixture was stirred 5 min, and was quenched with DMF (1.4 g, 18.6 mmol). Stirring was continued for 15 min at −78° C. and water was added. The THF was evaporated, Et2O was added and the organic phase was separated and washed with water, 1% HCl, water (3×) and brine. The organic phase was passed through a silica plug and toluene (20 mL) was added. Methyl(triphenylphosphonanylidene) acetate (3.34 g, 10.0 mmol) was added at 23° C. and the mixture was stirred for 12 h. The solvents were then evaporated, ether was added and the mixture was passed through a silica plug. The mixture was concentrated in vacuo and dried overnight via high vacuum and 585 mg of the above named enoate was obtained as a tan solid.

1. stirringStirring
2. waitwas continued for 15 min at −78° C.
3. customThe THF was evaporated
4. additionEt2O was added
5. customthe organic phase was separated
6. washwashed with water, 1% HCl, water (3×) and brine
7. additionwas added
8. stirringthe mixture was stirred for 12 h
9. customThe solvents were then evaporated
10. additionether was added
11. concentrationThe mixture was concentrated in vacuo
12. customdried overnight via high vacuum and 585 mg of the
13. customwas obtained as a tan solid

ORD record

ord-826f4a48f5454264a649938ca7255529

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06248783B1