hydrogenchloride Ambient temperature; Yield given;

piperidine; acetic acid in ethanol Knoevenagel Condensation; 3 h; Reflux;

1: 87 percent / POCl3 / a) RT, 30 min, b) heating, 30 min 2: 75 percent / piperidine / acetonitrile; benzene / 3 h / Heating 3: conc. HCl / Ambient temperature View Scheme

1: 67 percent / 47percent HI, conc. HCl / H2O / 60 h / Heating 2: 87 percent / POCl3 / a) RT, 30 min, b) heating, 30 min 3: 75 percent / piperidine / acetonitrile; benzene / 3 h / Heating 4: conc. HCl / Ambient temperature View Scheme

1: 75 percent / piperidine / acetonitrile; benzene / 3 h / Heating 2: conc. HCl / Ambient temperature View Scheme

1: 64 percent / sodium carbonate, 4-A molecular sieves / a) from 70 deg C to 100 deg C, 3 h, b) reflux, 11 h 2: 67 percent / 47percent HI, conc. HCl / H2O / 60 h / Heating 3: 87 percent / POCl3 / a) RT, 30 min, b) heating, 30 min 4: 75 percent / piperidine / acetonitrile; benzene / 3 h / Heating 5: conc. HCl / Ambient temperature View Scheme

1.1: sodium hydrogencarbonate / N,N-dimethyl-formamide / 50 - 70 °C / Inert atmosphere 2.1: trichlorophosphate / 0.25 h / 0 °C / Inert atmosphere 2.2: 0 - 20 °C / Inert atmosphere 2.3: 0.25 h / 0 - 20 °C / Inert atmosphere 3.1: piperidine / toluene; acetonitrile / 6 h / Reflux; Inert atmosphere 4.1: hydrogenchloride / water / 24 h / Inert atmosphere View Scheme

titrn. at pH7; addn. of amino acid resulted in complete restoration of fluorescence; fluorescence spectroscopy data;

titrn. at pH7; addn. of amino acid resulted in partial restoration of fluorescence; fluorescence spectroscopy data;

titrn. at pH7; addn. of amino acid resulted in partial restoration of fluorescence; fluorescence spectroscopy data;