LAARS SHUESTEIEN, DEKUULIZEN, AND VONK

Ht
3 re)

7
N-(CH4),2-~CH N—-(CH2))g—CH

HAC

(98) tridemorph-N- (99) 2, G-dimethyi~

97) tridemorph
Q%) P oxide morpholine

In cereals treated with tridemorph, the content drops from 20 ppm to
less than 0.05 ppm in 48 days [211]. No conversion products have been
identified so far, although indications were obtained for the formation of
hydroxylated metabolites [244].

F. Triforine

The systemic fungicide N, N'~bis-(1-formamido-2, 2, 2-trichloraothyl)-
piperazine (100) (Fig. 10) is particularly effective against powdery mildew
and rusts [212,213], After treatment, H-piperazine~ and 14¢-side-chain-
labeled triforine are rapidly translocated to the parts above ground and
accumulate in the leaves present at the time of treatment {214, 215, 219}.
Triforine decomposes more rapidly in dilute aqueous solution than in plants,
In water, the 1-formamido trichloroethy! groups were successively con-
verted into glyoxyl groups, yielding N-monoglyoxyl piperazine (101), N,N'-
diformylpiperazine (102), N, N'~diglyoxylpiperazine (103), and finally pipera-
zine (104) (Fig. 10) [219]. In different plant species triforine was metabo-
lized at diffcrent rates; in cucumber plants breakdown occurred more
rapidly than in barley plants {216-220}, According to the same authors
(216-219], triforine is metabolized in plants to four nonfungitoxic metabo-
lites, one of which was identified as piperazine. The three unknown metabo-
lites might bo identical with the degradation products in aqueous solution,
Since ring cleavage of the piperazine ring was not found to occur in barley
plants, piperazine may be the final terminal residue of triforine in plants
{217}.

.

G. Prothiocarb

Prothiocarb, S-ethyl N-(3-dimethylaminopropy!) thiocarbamate (105), is a
new systemic compound exerting a fungistatic effect on a variety of species
of Phycomycetes [221]. When (propyl-4c]prothiocarb was applied to the
roots of tomato plants via a nutrient solution or a soil drench, a large
amount of label, consisting mutinly of unchanged parent compound, was
rapidly translocated to the shoots. In addition to the main conversion

|
C)
N
H |
{HO),.C—C=0
(201)

|

HoH H H
Cho“ N= Cao {HO),C—c=0 (HO)C—E=0
N

¢ C0) C0)

| H |
ClkC—C—N—C=0 (HO),C—C=0
eH OH A 3 aa

Cl,5C—C—N—C=0
HH A

3
(100) , 103

FIG. 10. Proposed pathway for the metabolism of triforine (100) In plants.

product, N, N-dimethylpropane-1, 3-diamine (108), small amounts of 1-
methyl-tetrahydro~1,3-diazine-2-one and bis-(3-dimethylaminopropyl)-urea
were detected. In the rcots‘and in the nutrient solution, N,N-dimethylpro-
pane-1, 3-diamine represented the major fraction [245], .
Prothiocarb is degraded in soil, the formation of 4 CO» from the labeled
product being observed, The degradation occurs more readily in an alkaline
soil. The half-life of the fungicide was 59 and 144 days in a sandy and a
sandy loam soll, respectively, N, N-Dimethylpropane-1, 3-diamine (106),
diethyidisulfide, N-demethylprothiocarb (107), and 1-methyltetrahydro-1, 3-
diazine-2-one were tentatively identified as major metabolites (222, 245}.

H i H il
(CHa)aN(CHz)3N—C~SCoHy —_(CH)N(CH) NH H2N(CH2)3N—C—SC2Hg

. (106) N-N-dimethyipro- - (107) N-demethyl~
1 = =
(105) prothiocarb pane~1, 3-diamine prothiocarb

137