Pinaverium bromide53251-94-8100 % similar 2-Bromo-4,5-dimethoxybenzyl bromide53207-00-434 % similar 2-Bromo-4,5-dimethoxyphenylacetonitrile51655-39-132 % similar 2-Bromo-4,5-dimethoxyphenylacetic acid4697-62-530 % similar