Metrohm 711 Liquino - Manual (Page 57)

3 Introduction
711 Liquino, Instructions for use 51
3.2.11 SEQ – complex procedures under control
Example: the preparation of phenolazonaphthol. A short version of the syn-
thesis procedure might read as follows:
" 0.3 mol of a semi-concentrated hydrochloric acid is added to 0.1 mol
freshly distilled aniline. The temperature should remain below approx. 10°C.
After cooling the mixture to 0°C a 0.1 mol solution of NaNO
2
is added so
that temperature does not exceed 5°C. When this addition is complete 8%
β-naphthol solution (2 molar) is added. The temperature should not exceed
approx. 10°C.“
This procedure can be broken down into the following steps:
1. Temperature-controlled addition of semi-concentrated hydrochloric acid
to aniline (temperature below approx. 10 °C).
2. Pause for 5 minutes for cooling down to 0 °C.
3. Temperature-controlled diazotization (temperature below 5 °C).
4. Pause for 1 minute.
5. Temperature-controlled azo coupling (temperature below approx. 10 °C)
with β-naphthol.
The individual additions with temperature control can be carried out by an
XDOS method. However, the SEQ mode is available to automate the com-
plete procedure. It allows individual XDOS and also other methods to be
combined with each another. Pauses between steps and the control of oth-
er instruments are also possible.
Preconditions / Preparation
The following instruments and accessories are required:
• the 711 Liquino
• 3 Dosino 700s, each with a 50 mL dosing unit 710
• a printer with cable if the process is to be documented (see page 12)
• a four-neck flask
• a cooling device (if an appropriate cooling bath is used this can even be
switched on and off by the Liquino via the remote interface).
Dosing units which correspond to the tubings of the Dosinos used must be
defined. This process is described on page 22.
Method editing
For the three temperature-controlled additions three different XDOS meth-
ods must be defined, each of these stored under "USER METHOD“ and
then selected at the appropriate step in the SEQ method. Storing a method
which has been edited is described on page 64.
The way in which the first XDOS method (addition) is created can be found
in the section "XDOS – temperature-controlled addition“ on page 46.