In order to show any trends with reaction time or temperature more clearly, outlers were removed and the analysis repeated. Outliers were determined by considering the similarity of replicates. For each set of replicates, the Euclidean distance to the centroid was calculated. The mean distance plus 1.5 standard deviations was set as a threshold and any replicates with a distance greater than this were removed. This threshold was chosen as it removed the worst outliers from each dataset without taking out too many observations. Fig. shows the results for scaled data. The reaction time data now shows that MEK is most associated with greater amounts of products 10a, 11a, 14a, 15a and particularly 3a, while MeCN, BuCN and the dual solvent system are more related with greater amounts of products 18a and 19a (Fig 3A). The temperature data set shows an even greater difference in the amount of these side-products for MEK and the increasing trend with temperature can be seen more clearly for MeCN, BuCN and the dual solvent system. Although PCA gives a good indication of the products associated with the different solvents, interpretation is complicated when several variables have similar loadings. Importantly, it is the sum of the variables that contributes to the principal component in question. For example, a lower value for side-product 6a may be compensated for by a higher value for aniline 16a, leading to a similar score as a higher value for product 6a with a lower value for aniline 16a (Fig. ). To determine more specific relationships between solvents and reaction products, we employed correspondence analysis (CA). The median quantities were therefore calculated over replicate reactions and, for each solvent, counted the number of observations with high, medium and low quantities of each product over all temperatures and reaction times (a total of 20 for each solvent). Quantities less than a third of the full range (i.e. the maximum minus minimum value over all solvents) for a product were defined low, quantities between a third and two-thirds considered medium, with quantities above two-thirds of the range for product expressed as high.