I'm really new to LaTeX, and even newer to this website, so forgive me in advance for all the mistakes I may have made.
Here's my problem: I'm trying to replace the temporary labels (TMP1,...) in an .eps file (made with chemdraw), in a modus operandi chapter for my master thesis, and it doesn't work the way it should. The TMP labels indeed disappear, but the 1,2 and 3 expected to replace them appear on the left of the figure, not at all where they should be. Moreover, there's also a message saying "frag replacements", appearing on the graph in the dvi file. When I try to export it as pdf, it doesn't even change the labels and I get stuck with TMP1,2,3.
Here is the code:
\documentclass[a4paper,12pt,notitlepage]{book}
%Packages
\usepackage[utf8]{inputenc}
\usepackage[francais]{babel}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage{epstopdf}
%chemistry packages
\usepackage{chemstyle}
\usepackage{chemscheme}
\usepackage{chemschemex}
\usepackage{chemnum}
\usepackage{titling}
\usepackage{titlesec} %to correct spacing of chapters
\titleformat{\chapter}[display]
{\normalfont\huge\bfseries}{\chaptertitlename\ \thechapter}{20pt}{\Huge}
\titlespacing*{\chapter}{0pt}{-50pt}{20pt}
\titleformat{\chapter}[hang]
{\normalfont\huge\bfseries}{\chaptertitlename\ \thechapter:}{1em}{}
%Titre
\title{Partie expérimentale}
\author{Me}
\begin{document}
\chapter{Partie Expérimentale}
\section{Synthèse du thiéno[3,2-b]thiophène-2,5-diylbis((3-bromothiophèn-2-yl)méthanol)}
\begin{scheme}[ht]
\cmpd*{a}
\cmpd*{b}
\cmpd*{c}
\replacecmpd[TMP1]{a}
\replacecmpd[TMP2]{b}
\replacecmpd[TMP3]{c}
\includegraphics[scale=0.7]{Schema_Synthese_3.eps}
\caption{Schéma réactionnel 1}
\end{scheme}
\end{document}
And it gives the following result : 
Could you help me ?
EDIT: here is the .eps file

.epsfile? – Andrew Swann Feb 13 '17 at 12:56chemnumbut bypsfrag(this is mentioned in the manual!) – cgnieder Feb 13 '17 at 13:45psfrag's manual and not inchemnum's. Besides: this has been covered on TeX.sx about a million times (at least that's what it feels like) :) – cgnieder Feb 13 '17 at 15:51