Carbamates pirimicarb

In the six-membered series the pyrimidinyl carbamate pirimicarb (89) (69CI(L)1018) was made as the carbamate analogue of the pyrimidinyl phosphates, and is a highly selective aphicide.The industrial synthesis has been designed to avoid handling the carcinogenic dimethylcarbamoyl chloride (Scheme 13). The regenerated pyrimidinone (88) is extracted and recycled. 

MSPD involves blending a solid sample with solid particles, which simultaneously disrupt and disperse the sample. The underlying mechanisms of MSPD include sample homogenization, cellular disruption, exhaustive extraction, fractionation, and purification in a simple process. One carbamate (pirimicarb) and 12 organophosphorus pesticides were extracted by MSPD from honey, the sample was mixed with Florisil and anhydrous sodium sulfate in small glass columns, and subsequently extracted with a volume of n-hexane-ethyl acetate. ... 

Cambon, C., C. Declume, and R. Derache. 1979. Effect of the insecticidal carbamate derivatives (Carbofuran, Pirimicarb and Aldicarb) on the activity of acetylcholinesterase in tissues from pregnant rats and fetuses. Toxicol. Appl. Pharmacol. 49 203-208. 

Irradiation of isoprocarb and promecarb resulted in PFR to ortho- andpara-hydroxybenzamides. The photodegradation of analogous carbamate pesticides (bendiocarb, bendiocarb, ethiofencarb,furathiocarb,fenoxycarb, and pirimicarb) has also been examined, but in these cases, the most general result was formation of the corresponding phenols [298]. 

Pesticidal organic derivatives of carbamic acid, for which the formula is shown in Figure 15.8, are known collectively as carbamates. Some carbamate insecticides such as carbaryl, carbofuran, and pirimicarb have been in use for many years others, including Dunet, are relatively recent. Carbamate pesticides have been widely used because some are more biodegradable than the formerly popular organochlorine insecticides and have lower dermal toxicides than most common organophosphate pesticides. 

Pirimicarb has been widely used in agriculture as a systemic aphicide. Unlike many carbamates, it is rather persistent, with a strong tendency to bind to soil. 

Piproctanyl Bromide heterocyclic nitrogen, piperidine, quartenary ammonium Pirimicarb carbamate, pyrimidine Pirimiphos-ethyl pyrimidine, phosphoro organic, phosphoro thioate... 

Typically, insecticides represent about 30% of the market in agrochemicals. Activity depends on the ability to penetrate insects rapidly and reach sites of action in membranes of nerve cells. Insecticides are more soluble in fats than in water. The aryl amine insecticides include carbamic esters, such as pirimicarb (104), a diazine derivative (Scheme 23). It is of short-to-moderate persistence, but more selective than organophosphorus compounds. Acylation of A-methyl-l-naphthylamine, or reacting the chloroacetamido derivative with potassium fluoride in glycerol, affords the insecticide and acaricide known as nissol (105). 

Some carbamates (carbosulfan, benfuracarb, carbofuran, pirimicarb, diethofencarb, and diuron) and phenylurea pesticides (monuron and monolinuron) were sampled from different fruit juices by using 50-pm carbowax-templated resin (CW-TPR) and a 60-pm PDMS/DVB SPME fiber (Sagratini et al., 2007). The fiber desorption into the SPME-LC/MS interface chamber previously filled with 70% methanol and 30% water, was performed in static mode. 

Figure 9.11. Carbamates determined by LC-atmospheric pressure chemical ionization (APCI) or electrospray (ES) in positive-ion mode (Fern ndez et al., 2000). (24) car-bofuran, (25) ethiofencarb, (26) methiocarb, (27) fenobucarb, (28) isoprocarb, (29) fenoxycarb, (30) diethofencarb, (31) metholcarb, (32) propoxur, (33) pirimicarb, (34) oxamyl, (35) thiobencarb. Structure of carbaryl is reported in Fig. 9.1.

Carbamic acid, dimethyl-, 2-(dimethylamino)-5,6-dimethyl-4-pyrimidinyI ester Pirimicarb 3633, 4249, 4271a ... 

The contamination of fruits and vegetables with pesticides became a problem with the increased application of pesticides because of an intensified agriculture. So the comparison of APCI and ESI-LC-MS for the determination of 10 pesticides of carbamate type (pirimicarb, carbofuran, 3-hydroxycarbofuran, aldicarb, and its metabolites, the sulfoxide and the sulfone), besides others in fruits, met the... 

Nine carbamates were baseline resolved and exhibited excellent peak shapes on both a cyanopropyl colunm (7-10% IPA in hexane gradient) and on a silica column (A = 220nm) using a 10-min 7/93-> 9/91 IPA/hexane gradient [634). Striking retention difil ences occurred. For example, pirimicarb eluted 3min on the cyanopropyl column and at 10 min on the silica colunm. Peak shapes and overall resolution was also significantly better on the cyanopropyl column as compared with the silica colunm. 

Pirimicarb Dimethylamino carbamoyl chloride Carbamic insecticide... 

Irradiation of the herbicide propanil gives rise to complex mixtures containing the products arising from PFR of the anilide moiety [184]. In the carbamate series, isoprocarb and promecarb give rise to the ortho- andpara-hydroxybenzamides, whereas bendiocarb, thiobencarb, furathiocarb, fenoxy-carb, and pirimicarb lead mainly to the corresponding phenols [185]. 

Carbamates Aldicarb, bendiocarb, benfuracarb, ethiophencarb, furathiocarb, carbofuran, carbosulfan, methomyl, oxamyl, pirimicarb... 

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