Products

 

PIRIMIPHOS-METHYL

 

Insecticide, acaricide
organophosphorus
 

NOMENCLATURE
Common name pirimiphos-methyl (BSI, E-ISO, ANSI, ESA); pyrimiphos-méthyl ((m) F-ISO)
IUPAC name O-2-diethylamino-6-methylpyrimidin-4-yl O,O-dimethyl phosphorothioate 
Chemical Abstracts name O-[2-(diethylamino)-6-methyl-4-pyrimidinyl] O,O-dimethyl phosphorothioate 
CAS RN [29232-93-7]  EEC no. 249-528-5  Development codes PP511 (ICI)  Official codes OMS 1424 

PHYSICAL CHEMISTRY
Composition Tech. material is 88% pure.  Mol. wt. 305.3  M.f. C11H20N3O3PS  Form Straw-coloured liquid.  M.p. 15-18 ºC (tech.)  B.p. Decomposes on distillation.  V.p. 2 mPa (20 ºC); 6.9 mPa (30 ºC); 22 mPa (40 ºC)  KOW logP = 4.2 (20 ºC, unionised)  Henry 6 ´ 10-2 Pa m3 mol-1 (calc.)  S.g./density 1.17 (20 ºC); 1.157 (30 ºC)  Solubility In water 11 (pH 5), 10 (pH 7), 9.7 (pH 9) (all in mg/l, 20 ºC). Miscible with most organic solvents, e.g. alcohols, ketones, halogenated hydrocarbons.  Stability Hydrolysed by concentrated acids and alkalis; DT50 2-117 d (pH range 4-9, most stable at pH 7). In sunlight, aqueous solution had DT50 <1 h.  pKa 4.30  F.p. >46 ºC 

APPLICATIONS
Biochemistry Cholinesterase inhibitor.  Mode of action Broad-spectrum insecticide and acaricide with contact and respiratory action. Penetrates the leaf tissue and exhibits translaminar action.  Uses Control of a wide range of insects and mites in warehouses, stored grain, animal houses, domestic and industrial premises; chewing insects, sucking insects, boring insects, and mites on vegetables, ornamentals, bulb flowers, sugar cane, maize, sorghum, rice, citrus and other fruit, olives, vines, alfalfa, cereals, etc.; and glasshouse pests (especially whitefly, thrips, mealybugs, aphids, and mites) on tomatoes, cucumbers, capsicums, aubergines, and other glasshouse crops.  Formulation types AE; DP; EC; FU; HN; KN; LS; SG; UL.  Compatibility Miscible with common insecticides and fungicides. Mixing with strongly alkaline or acidic substances should be avoided.