Figure 2: General route for synthesis of 1–10.
From: Hydrochromic molecular switches for water-jet rewritable paper
Preparation of oxazolidines 1–10 starts with various substituted phenylhydrazines (S1–10); they are converted to corresponding 2,3,3-trimethylindolenine (A1–10) first, indoleninium bromides (B1–10) next, condensation intermediates (C1–10) then and finally to the desired target molecules (1–10). ‘aqu.’ is the abbreviation for aqueous solution.
