Cartap hydrochloride

Cartap hydrochloride is used to control sucking and chewing insects (particularly Lepidoptera and Coleoptera), at almost all stages of development, on many crops including rice, potatoes, cabbage and other vegetables. It is also used on soya, peanuts, sunflower, maize, sugar beet, wheat, pearl barley, pome, stone and citrus fruit, vines, tea, chestnuts, ginger, cotton and sugar cane.

Insecticide: Cartap hydrochloride is used to control chewing and sucking insects on many crops, including rice, potatoes, cabbage and other vegetables, soy beans, peanuts, sunflowers, maize, sugar beet, wheat, pearl barley, pome fruit, stone fruit, citrus fruit, vines, chestnuts, ginger, tea, cotton, and sugar cane. Not currently registered in the U.S. or registered for use in EU countries. There are approximately 15 global suppliers.

CADAN®; CALDAN®; KRITAP®; NTD 2®; PADAN®; PATAP®; SANVEX®; THIOBEL®; TI1258®; VEGETOX®

Poison by ingestion andintravenous routes. An experimental teratogen. Aninsecticide. When heated to decomposition it emits verytoxic fumes of NOx, SOx, and HCl.

Nereistoxin, 4-N,N-dimethylamino-1,2-dithiolane, is produced from cartap hydrochloride as a main product through photoreaction under UV irradiation in aqueous and methanolic solutions, and on glass and silica gel surfaces. Cartap hydrochloride is also oxidized with N-bromosuccinimide (NBS) to give nereistoxin.

Cartap hydrochloride was hydrolysed to dihydronereistoxin (2) when automatically titrated with sodium hydroxide solution and subsequently oxidised to nereistoxin (3) (see Scheme 1). The hydrolysis was a base catalysed pseudo-first-order reaction with a half-life of 10 minutes at pH 7 and 25 °C. Nereistoxin was so stable that no degradation was observed after 24 hours at 100 °C and with pH in the range 1-4. The DT₅₀ s of nereistoxin at 100 °C and at the higher pH values of 7/10 and 12.3 were 26,20 and 7.9 hours, respectively. It was predicted that nereistoxin (3) would be hydrolysed by alkali to the 3-mercaptopropanesulfenic acid (4) which would be oxidised to the sulfinic acid (5) and thence to the sulfonic acid (6) (Asahi and Yoshida, 1977).
An aqueous solution of unlabelled cartap hydrochloride was exposed to sunlight for a period of 5 days. Analysis was by IR, UV and MS methods. Three products were isolated after irradiation and the major of these was identified as a polymer of nereistoxin (7) and represented 80% of applied dose. The polymer (7) was not toxic to fish (Oryzias latips).
Cartap was hydrolysed to nereistoxin (3) via dihydronereistoxin (2). Nereistoxin (3) was converted into the polymer (7) probably after photolytic formation of a nereistoxin diradical as shown in Scheme 1 (Obayashi and Asaka, 1983).