1.1: pyridine / 20 °C 2.1: methanol; dichloromethane / 0.5 h 2.2: Dowex H+ View Scheme

Stage #1: <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '130503', constants.ctx, '0')">2,6-di-tert-butyl-4-methylpyridine</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1730800', constants.ctx, '0')">dichloromethane</a> <br />T=20&deg;C;&nbsp;0.333333&nbsp;h;&nbsp;&nbsp;Inert atmosphereMolecular sieve;&nbsp;<br />Stage #2: <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '5190642', constants.ctx, '0')">dimethyl-(methylthio)-sulphonium trifluoromethanesulphonate</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1730800', constants.ctx, '0')">dichloromethane</a> <br />T=0 - 20&deg;C;&nbsp;1&nbsp;h;&nbsp;&nbsp;Inert atmosphereMolecular sieve;&nbsp;<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: pyridine / 1 h / 0 &deg;C / Cooling with ice<br />2.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 1.5 h / 0 &deg;C / Cooling with ice<br />3.1: 2,6-di-tert-butyl-4-methylpyridine / dichloromethane / 0.33 h / 20 &deg;C / Inert atmosphere; Molecular sieve<br />3.2: 1 h / 0 - 20 &deg;C / Inert atmosphere; Molecular sieve<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: water; acetic acid / dichloromethane / 50 h / 20 - 50 &deg;C<br />2.1: 2,6-di-tert-butyl-4-methylpyridine / dichloromethane / 0.33 h / 20 &deg;C / Inert atmosphere; Molecular sieve<br />2.2: 1 h / 0 - 20 &deg;C / Inert atmosphere; Molecular sieve<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 1.5 h / 0 &deg;C / Cooling with ice<br />2.1: 2,6-di-tert-butyl-4-methylpyridine / dichloromethane / 0.33 h / 20 &deg;C / Inert atmosphere; Molecular sieve<br />2.2: 1 h / 0 - 20 &deg;C / Inert atmosphere; Molecular sieve<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: pyridine / 1 h / 0 &deg;C / Cooling with ice<br />2.1: water; acetic acid / dichloromethane / 50 h / 20 - 50 &deg;C<br />3.1: 2,6-di-tert-butyl-4-methylpyridine / dichloromethane / 0.33 h / 20 &deg;C / Inert atmosphere; Molecular sieve<br />3.2: 1 h / 0 - 20 &deg;C / Inert atmosphere; Molecular sieve<br /> <br /> &nbsp;