Pendimethalin

Selective herbicide, Control of most annual grasses and many annual broad-leaved weeds, at 0.6-2.4 kg/ha, in cereals, onions, leeks, garlic, fennel, maize, sorghum, rice, soya beans, peanuts, brassicas, carrots, celery, black salsify, peas, field beans, lupins, evening primrose, tulips, potatoes, cotton, hops, pome fruit, stone fruit, berry fruit (including strawberries), citrus fruit, lettuce, aubergines, capsicums, established turf, and in transplanted tomatoes, sunflowers, and tobacco. Applied pre-plant incorporated, pre-emergence, pre-transplanting, or early post-emergence. Also used for control of suckers in tobacco.

Pendimethalin is a selective herbicide registered for control of broadleaf weeds and grassy weed species on a variety of agricultural crops, turf, and ornamentals. Pendimethalin disrupts the process of mitosis in the growth of shoots and roots.

A mixture of 4-chloro-3,5-dinitro-o-xylene (0.61 mol), 3-pentaneamine (1.82 mols), and xylene (1,400 mL) is brought to reflux. After refluxing overnight, the reaction mixture is cooled and filtered. The precipitate is washed with petroleum ether. The filtrate and washings are combined, washed with 500 ml of 10% hydrochloric acid, and finally with 2 liters of water. The organic layer is separated and dried. Removal of the drying agent and the solvent leaves an orange oil which crystallizes with the addition of methanol. A yellow orange solid with melting point of 56-57 °C is collected in about 85% yield.

Obtained from 3,4-xylidine by alkylation and dinitration.