[Tex/LaTex] chemnum package

Question

The following minimal code using the chemnum package was designed to replace TMP1, TMP2 and TMP3 in an eps file made by ChemDraw by numbers:

\documentclass{article}
\usepackage{graphicx}
\usepackage[runs=2]{auto-pst-pdf}
\usepackage{chemnum}

\newenvironment{scheme}{}{}

\begin{document}

\begin{scheme}
    \cmpdref{ref:nucleophile1}
    \cmpdref{ref:nucleophile2}
    \cmpdref{ref:nucleophile3}
    \includegraphics[scale=0.6]{aziridineopening}
\end{scheme}

\end{document}

A copy of the eps file can be found here. Is this problem due to my eps file or my code?

Answer 1

(Summarising my comments into an answer.)

The most common issue when using auto-pst-pdf is a failure of the conversion after the LaTeX run. Here, in the log we find

Package auto-pst-pdf Warning: 
    Creation of minimum-pics.pdf failed.
This warning occured on input line 124.

As the file compiles without errors with pdfLaTeX, the most likely explanation is that pdfcrop is failing to run: this is the final step of the conversion process. In particular, pdfcrop will not work 'out of the box' on Windows. Thus a solution may well be to use

\usepackage[crop=off]{auto-pst-pdf}