Patent ID: 8841460

Claim:
A compound, or a salt thereof, having the formula wherein Y is n is 1 or 2; each R is independently H, alkyl, substituted alkyl, a polyether moiety, carboxyl, substituted carboxyl, carbamate, substituted carbonate, carbonyloxy, alkoxy, substituted alkoxy, haloalkyl, halogen, nitro, amino, aryloxy, cyano, hydroxyl, or sulfonyl; R 1 is H, lower alkyl or aralkyl; R 2 is selected from H, acyl, aralkyl, phosphonyl, —SO 2 R 3 ; —C(O)R 5 ; —C(O)OR 7 or —C(O)NR 9 R 10 ; R 3 ; R 5 ; R 7 ; R 9 and R 10 independently are selected from H, lower alkyl, aralkyl or aryl; and R 20 is selected from alkyl, substituted alkyl, a polyether moiety, carboxyl, substituted carboxyl, carbamate, substituted carbonate, carbonyloxy, alkoxy, substituted alkoxy, haloalkyl, halogen, nitro, amino, aryloxy, cyano, hydroxyl, or sulfonyl.