Yield:6623-56-9 93.65%

Reaction Conditions:

in chloroform;isopropyl alcohol at 63; for 4 h;

Steps:

1 Preparation of quaternary ammonium salt

A 5000 ml four neck round bottom flask with water condenser and calcium chloride tube was charged with Hexamine (210.28 gm), chloroform (1200 ml), 3,4-dihydroxy-a- chloroacetophenone (250 gm) and isopropanol (1000 ml) at room temperature. The reaction mass was gently heated at 63°C for 4 hours. The reaction was monitored by TLC. The reaction mass was cooled to room temperature and filtered to get solid. The solid was washed with acetone and dried at 50°C for 4 hours to obtain quaternary ammonium salt which was used in the next step without purification.Yield - 410 gm (93.65%)Nature - off white solidm.p. - 180 to l82°CNMR (DMSO-d6): - δ =4.51 - 4.75 (m, 8H), 5.39 (s, 6H), 6.92 (d, 1H, J= 7.5 Hz), 7.37 - 7.42 (m, 2H), 9.67 (s, br, 1H), 10.44 (s, br, 1H)

References:

WO2013/8247,2013,A1 Location in patent:Page/Page column 9; 10