1,2,4-triacetoxybenzene (Aldrich)
dimethyl sulfate
NaOH

1,2,4-triacetoxybenzene (50 g, 0.198 mol) was dissolved in a mixture of methanol (100 cm³) and dimethyl sulfate (175 cm³, 1.849 mol). With mechanical stirring and ice cooling, a solution of NaOH (150 g, 3.75 mol) in water (150 cm³) was added so that the temperature remained between 25 and 30 ºC. After the addition was complete stirring was continued for a further 1 h then the mixture was allowed to stand overnight. Water (300 cm³) was added and the product was extracted with ether (4 x 100 cm³). The organic extract was dried (MgSO₄), filtered,  and evaporated to give a brown oil which was distilled to give a colourless oil  bp 62-64 ºC/0.05 mm, 29.4 g (88% yield, lit: 90%). 

A literature procedure worked with no problems.   This compound was prepared by the method of H D Locksley and I G Murray, J Chem Soc C, 1970, 392-398 doi:10.1039/j39700000392, which is based on that of T R Govindachari, K Nagarajan and P C Parthasarathy, J Chem Soc, 1957, 548-551 doi:10.1039/jr9570000548.

δ_H (CDCl₃, 200 MHz) 6.78d (8.7), 6.50d (2.9), 6.38dd (8.7, 2.9), 3.84s, 3.82s, 3.76s

H D Locksley and I G Murray, J Chem Soc C, 1970, 392-398 doi:10.1039/j39700000392

T R Govindachari, K Nagarajan and P C Parthasarathy, J Chem Soc, 1957, 548-551 doi:10.1039/jr9570000548