Firstly, 11.79 g HBP-12 (0.01 mol), 19.11 g MPA (0.18 mol), 50 mL toluene, and 0.54 g p-toluenesulfonic acid
were added into a four-necked flask equipped with stirrer, cooler, nitrogen inlet, and water-trap (Dean-Stark) to react at 80[degrees]C for 10 h.
After that, 5 mL of the solution of 1% (w/w) p-toluenesulfonic acid
in ethanol was added to the content of each sample vial which was then immediately sealed with a magnetic screw cap lined with a butyl/polytetrafluoroethylene septum (Supelco) and shaken for 2 minutes (until the content becomes completely dissolved).
Method B: Adipic acid, n-butanol with a mole ratio of 1:5 and 5% p-toluenesulfonic acid
were refluxed in a flask equipped with a water separator.
The first step to obtain the desired compounds was the coupling reaction between 2 and 4, catalyzed by p-toluenesulfonic acid
, according to the method described by Mechoulam et al.
Methylbenzene as water-carrying agent and p-toluenesulfonic acid
as a catalyst were added.
3-Methoxythiophene (26.86 g, 235 mmol), p-toluenesulfonic acid
monohydrate (0.91 g, 4.78 mmol), and 1dodecanol (39.21 g, 210.4 mmol) were mixed together in a 1000 mL round bottom flask and refluxed at 92[degrees]C at low pressure (220 mTorr-132 mTorr) for 3.5 hours.
In the past decades, a variety of conditions have been established for the synthesis of dipyrromethanes in the presence of various catalysts such as p-toluenesulfonic acid
, Ti[Cl.sub.4] , C[F.sub.3]COOH  and pyrrolidinium tetrafluoroborate .
The PPy/ nanoG/[RE.sup.3+] nanocomposites are prepared using different molar ratios of nanoG and [RE.sup.3+] via in-situ polymerization method with p-toluenesulfonic acid
as a dopant and Fe[Cl.sup.3] as an oxidant.
Method B: Tartaric acid (0.1mol) n-butanol (0.25mol) cyclohexane (30mL) p-toluenesulfonic acid
(0.6g) were added into a flask equipped with a water separator.
In Shanghai, 1,10-decanediol, p-toluenesulfonic acid
, N,N-dimethylformamide (DMF), trimethylol aminomethane, and ibuprofen were purchased from Sinopharm Groups of China, and they were used as received.