Ethofumesate is a benzofuran sulfonate herbicide used on sugar beets, pasture, tobacco, and sunflowers. It is synthesized via two routes, one involving the reaction of p-benzoquinone, isobutyraldehyde, and ethanol, and the other involving the reaction of isobutyraldehyde and morpholine followed by sulfonylation and chlorination.

1. 840 Pesticides Synthesis Handbook
Ethofumesate
Uses: herbicide, sugar beet, pasture, tobacco, sunflowers
Trade names: Nortron, Tramat (Schering)
Type: benzofuran, sulfonate
Synthesis:
0 [~~~,~ + --CII--C--C--II [i
0 C
base
!
HO -c-
p-benzoquinone isobutyraldehyde
+
t !
-c-c-OH ethanol
t I
i I
-c-
~~Jx /o-'~-c'-
9 - o i a j
ox ICI methane
IS, sulfonyl
o c- chloride
I
o I
I I| .--c-
-c-S-o ~ ,
' 'o' -c-
I I
O--C--C-
- 0 / I I
ethofumesate

2. Diverse Chemical Functions 841
alternate route :
I ! I
--- C--- C--- C---
i I '
/c
o
t%..
f
I I
--c---c--c--
i U '
c--
I
isobutyraldehyde morpholine
o
II
0II
o
l
0
i II I--C--
--c--S--o
' N o
o /
o Cl
% /
s
0 C--
I
I
-c-
Ho ~-/_~
N o
o X.._../
I I
--c--c--Oil
I I
~HCI
o
I II I-,C--
.--c--S--o
'
~ --C--
I . I
O---C--C---
I I