6.994 (1, 1H, ddd, J=7.936, J=1.630, J=1.198), 6.994 (2, 1H, ddd, J=7.936, J=1.630, J=1.198), 6.994 (4, 1H, ddd, J=7.936, J=1.630, J=1.198), 6.994 (5, 1H, ddd, J=7.936, J=1.630, J=1.198), 2.229 (7, 3H), 2.229 (8, 3H)

So this doesn’t match what’s on the visual output (and I’m frankly not sure how to paste that into a blog comment)…perhaps that’s just a bug, or my misuse of the software.
But, let me try to describe what I see as an output, from aromatic region upfield to 0ppm:
1) A sort-of quartet ~7.015ppm
2) Another complementary sort-of quartet at ~6.9985ppm
3) A singlet at ~2.23ppm

I looked up the reported chemical shift (notice I left it as singular, since I see these protons as degenerate, am I naïve?) for the aromatic protons. The reported shift (solvent dependent of course) ranges from 6.94ppm to 7.06ppm. A good friend of mine reminded me that you could see the long-range coupling between the methyl and aromatic protons. But what else?

I suppose I want to make a point here:

If the prediction can’t handle simple structures like para-Xylene, I’d shudder to think of its prediction performance on structures the discerning chemist would use to test its accuracy.

So why the rant? There are three issues here:
1) Sometimes I feel (and maybe I’m simply sensitive to it) that it’s assumed in some circles that commercial scientific software vendors are the “bad guys,” and that for whatever product there is on the market, there is a viable, free alternative. As I’m sure my counterparts at Modgraph and elsewhere would attest: we put a fair amount of money (time, resources, etc.) into our prediction applications. And although ACD/Labs and Modgraph have an ongoing debate as to which of us have a more accurate predictor, I’d say that these commercial results, while not free, provide reasonably accurate results. When and where we don’t provide accurate results, we strive to improve. Tony, you can attest to the hard work (10 years worth!) to get the ACD/Labs prediction applications to where they are today!
2) I noticed an earlier comment to the effect of, “I wish this stuff would have been around when I was studying chemistry.” No slight to the commentor intended, but I’d personally find prediction results like these to be a detriment rather than a benefit.
3) Tony, at what point will negative comments on the prediction capabilities you’ve exposed lead you to conclude it’s not ready for “prime time?” You and I both know very well that quality matters, and I believe these prediction capabilities do NOT meet your quality standards.

I’m welcome to hearing feedback.

db