Belle is an affiliate of Cornerstone located in Belle, West Virginia. Belle is a key producer of methylamines—Monomethylamine ... (MMA), Dimethylamine (DMA) and Trimethylamine (TMA)—and the sole North American producer of methylamides—Dimethylformamide (DMF) and Dimethylacetamide (DMAc)—that are used in a wide array of industries. read more