P 1704 (OTTO) Phenylmagnesium chloride solution 2.0 M Diethyl ether Cas 100-59-4 -used in chemical research used primarily to add an iso-propyl group to carbonyl groups. This reagent can also be used as a strong base in aprotic solvents. It is also used as a Grignard reagent in greener solvent, 2-methyltetrahydrofuran (2-MeTHF).