ethyl 4-cyclopropyl(hydroxy)methylene-3,5-dioxocyclohexanecarboxylate

ethyl 4-(cyclopropylhydroxymethylene)-3,5-dioxocyclohexanecarboxylate

C₁₃H₁₆O₅

White, odourless solid; (tech. is a yellow to red-brown liquid (30℃) and a solid-liquid melt (20℃), with a slight sweet odour).

36 ℃

>270 ℃

1.6 mPa (20 ℃); 2.16 mPa (25 ℃) (OECD 104)

133 ℃ (1013 mbar) (EEC A9)

1.215 g/cm³ (20 ℃)

In water 2.8 (pH 4.9), 10.2 (pH 5.5), 21.1 (pH 8.2) (all in g/l, 25 ℃). In ethanol, acetone, toluene, n-octanol 100%, n-hexane 5% (25 ℃).

Heat-stable up to boiling point. Photolytically and hydrolytically stable under normal environmental conditions (pH 6-7, 25 ℃). Less stable in alkali.

5.4 ×10^-4 Pa m³ mol^-1

= 1.60 (pH 5.3, 2

4.57

Inhibits 3b-hydroxylation of GA20 to GA3 in gibberellin biosynthesis. The reduced level of gibberellins leads to growth retardation of plants.

Plant growth regulator and retardant, which reduces stem growth by inhibition of internode elongation. Absorbed by the foliage, with translocation to the growing shoot.

Used for the prevention of lodging in cereals and in winter oilseed rape, at 0.1-0.3 kg/ha. Also used in turf, at 0.15-0.5 kg/ha, to reduce mowing; and as a maturation promoter in sugar cane at 0.1-0.25 kg/ha.

Could cause inhibition or growth stoppage of some plants, e.g. grasses, aquatic plants and algae.

Compatibility of little importance because of late timing of application; compatible with certain late-season fungicides.

Acute oral LD₅₀ for rats 4460 mg/kg.

Acute percutaneous LD₅₀ for rats >4000 mg/kg. Not irritant to skin or eyes of rabbits. Non-sensitising to skin (guinea pigs).

LC₅₀ (48 h) for rats >5.3 mg/l.

(2 y) for rats 115 mg/kg b.w. daily; (18 mo) for mice 451 mg/kg b.w. daily; (1 y) for dogs 31.6 mg/kg b.w. daily.

0.316 mg/kg b.w.

WHO (a.i.) U (company classification)

LD₅₀ for ducks and quail >2000 mg/kg. LC₅₀ (8 d) for ducks and quail >5000 ppm.

LC₅₀ (96 h) for trout, carp, bluegill sunfish, catfish, fathead minnow 35-180 mg/l.

LC₅₀ (96 h) 142 mg/l.

Low toxicity to earthworms; LC₅₀ >93 mg/kg.

Rapid metabolism to the acid, which remains by far the predominant metabolite.

In rats, goats and hens, 90% excretion occurs within 24 h, all as the acid metabolite.

In soil, the ester undergoes rapid degradation, DT₅₀ <1 d. The acid has Kd values 1.5-16, Koc 140-600. Further metabolism is rapid, DT₅₀ typically 2-5 w. Within 4-8 w, 50% is mineralised to CO₂.

All methods use hplc, for both ester and acid metabolite.