591-22-0

CLEAR YELLOW LIQUID

3,5-Lutidine is a reactant used in the synthesis of phthalazine and pyrazine compounds, as well as other pharmaceuticals.

Synthesis, p. 573, 1994 DOI: 10.1055/s-1994-25526

Flammable

Dry 3,5-lutidine with sodium and fractionally distil it through a Todd column (p 11) packed with glass helices. Dissolve (100mL) in dilute HCl (1:4) and steam distil this until 1L of distillate is collected. Excess conc NaOH is added to the residue which is again steam distilled. The base is extracted from the distillate, using diethyl ether. The extract is dried over K2CO3, and distilled. It is then fractionally crystallised by partial freezing. The hydrochloride has m 229o(sublimes at 190-231o), and the picrate has m 242-243o(dec, from H2O), 249-250o(dec, from AcOH). [Beilstein 20 II 161, 20 III/IV 2788, 20/6 V 60.]

The initial threshold screening level (ITSL) for 3,5-lutidine is 0.1 μg/m3 (annual averaging time).