6984. Paclobutrazol

Nomenclature

CAS number: 76738-62-0
(αR,βR)-rel-β-[(4-Chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol; 1-tert-butyl-2-(p-chlorobenzyl)-2-(1,2,4-triazol-1-yl)ethanol; (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol; ICI-PP-333; PP-333; Bonzi (Syngenta); Cultar (Zeneca Ag Prod); Parlay (Zeneca Ag Prod); Trimmit (Zeneca Ag Prod).
C15H20ClN3O; mol wt 293.79.
C 61.32%, H 6.86%, Cl 12.07%, N 14.30%, O 5.45%.

Description and references

Plant growth regulator with fungicidal activity. Prepn: B. C. Baldwin et al., DE 2734426; S. Balasubramanyan, M. C. Shephard, US 4243405 (1978, 1981 both to ICI). Physical properties and biological activity: B. G. Lever et al., Proc. Br. Crop Prot. Conf. - Weeds 1982, 3. Resolution and activity of isomers: B. Sugavanam, Pestic. Sci. 15, 296 (1984). GC determn in plant tissue: E. A. Stahly, D. A. Buchanan, HortScience 21, 534 (1986). Comparison with daminozide, q.v., of effect on apple trees: G. R. Stinchcombe et al., J. Hortic. Sci. 59, 323 (1984).

Chemical structure

Properties

White crystalline solid, mp 165-166°. d 1.22. Vapor pressure at 20°: 1×10-6 Pa. Soly: water 35 mg/l, methanol 15%, propylene glycol 5%, acetone 11%, cyclohexanone 18%, methylene dichloride 10%, hexane 1%, xylene 6%.

Use

Plant growth regulator.