\documentclass[12pt,border=3pt,tikz,class=scrartcl,multi=false]{standalone}
\usepackage{times}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage{mathtools,amssymb,gensymb}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\usetikzlibrary{positioning,calc,arrows,fit,backgrounds,decorations.text,shapes}
 
\usepackage{chemfig,chemmacros}
\renewcommand*{\familydefault}{\sfdefault}
\renewcommand*\printatom[1]{\ensuremath{\mathsf{#1} } }
\setatomsep{2.5em}
\setdoublesep{.6ex}
\setarrowdefault{,1,ultra thick}
\setbondstyle{very thick,cap=but}
\definesubmol\nobond{-[0,.6,,,draw=none]}

\usepackage[american]{circuitikz}
 
\pagestyle{empty}
\thispagestyle{empty}
\begin{document}
\renewcommand{\baselinestretch}{1}
\begin{tikzpicture}[thick, >=latex']
	\node (n1) {
	\schemestart[][west]
	\chemfig{-(=[:-60]O)-[:60](-[::-60])-[::60]}
    \arrow{->[\parbox{3.5cm}{\small\chemfig{NaCN\,NH_4Cl\,MgSO_4}\\\chemfig{NH_3\,/\,MeOH}\\$30^\circ$C/$4$hrs}]
[\parbox{3.5cm}{\small2. L-tartaric acid\\MeOH, rt, 72hrs}]}[,2.5]
    \chemfig{H_2N-[:30](<:[3])(-[:-30]C~[::0]N)<[1](-[::-60])-[::60]}
    \arrow{0}[,0]\+
    \chemfig{HOOC-[:30](<[2]OH)-[:-30](<[6]OH)-[:30]COOH}
    \arrow{->[][*{0}\parbox{3cm}{\small\chemfig{NaOH,\,CH_2Cl_2}\\then \chemfig{H_2SO_4} (aq)}]}[-90]
    \chemleft[\subscheme{
    	\chemfig{N^{\scriptstyle+}(-[3]H)(-[:190]H)(-[6]H)-[:30](<:[3])(-[:-30]C~[::0]N)<[1](-[::-60])-[::60]}
        \arrow{0}[-90,0.1]
        \chemfig{HSO_4^\ominus}
    }\chemright]
   \arrow{->[*{0.south}\parbox{2.7cm}{\small1. 100\degree C, 20hrs\\2. \chemfig{NaOH}\\3. \chemfig{EtOCOCl} }]
[*{0.north}\parbox{2.7cm}{\small4. \chemfig{HCl}\\5. \chemfig{DCH} }]}[180,1.95]
   \chemfig{H-N^{\scriptstyle+}(-[:-30]H)
   (-[1]*6(------)  )
   -[6]*6(------)
   }
   \chemfig{EtO-[:30](=[2]O)-[:-30]N(-[6,0.3,,,draw=none]H)-[:30](<:[3])(-[:-30](=[::60]O)-[::-60]O^\ominus)
<[1](-[::60])-[::-60]}
\schemestop
	};
\end{tikzpicture}
\end{document}