disodium hydrogenphosphate; hydrogen; palladium on activated charcoal in methanol T=100°C; P=760 Torr; 2 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

2: H2 / 10 percent Pd/C / ethyl acetate / 0.75 h / 60 °C / 1520 Torr View Scheme

With  potassium hydroxide in  ethanol 15 h;  Heating;   

Multi-step reaction with 2 steps 1: 89 percent / SnCl4 / CH2Cl2 / -78 °C2: 80 percent / 50 percent KOH / ethanol / 15 h / Heating