Dariusz Cal

A new synthesis of enaminoketones

Abstract A new and efficient synthesis of enaminoketones is described. E,Z β-chloroacroleine derivatives react with secondary amines to produce enaminoketones. The reaction was essentially studied with β-trifluoromethylacroleines.

Synthesis of Phosphorylated Enaminoketones and Their Application in the Preparation of Trifluoromethyl-Functionalized 2-Phosphonopyrroles

Abstract New trifluoromethyl-functionalized 2-phosphonopyrroles were obtained by 5-exotrig cyclization of trifluoromethyl and phosphonyl functionalized enaminoketones. GRAPHICAL ABSTRACT

New Method for the Generation and Trapping of 1-Azabicyclo[1.1.0]butane. Application to the Synthesis of 1,3-Dinitroazetidine

Abstract 1-Azabicyclo[1.1.0]butane (1) has been prepared via a two-step, one-pot procedure that involves (i) reaction of a heptane solution of allylamine with N-chlorosuccinimide at 0 °C followed by (ii) codistillation of the product from basic solution along with heptane-octane. Compound 1 thereby obtained was extracted from the distillate by using cold aqueous NaNO2. Subsequent treatment of the aqueous extract with cold concentrated aqueous HCl afforded N-nitroso-3-nitro-azetidine (4) in 5.5% yield. Oxidation of 4 with 100% HNO3 produced N,3-dinitroazetidine (5, 90%). This reaction sequence constitutes a formal synthesis of 1,3,3-trinitroazetidine (TNAZ), an important energetic material.

A New Route to 3-Phosphonylpyrazoles

The regioselective synthesis of 3-diethoxyphosphonopyrazoles has been accomplished through the addition of aryl or alkyl hydrazines to (3-ethoxyacryloyl)phosphonic acid diethyl ester. An example of hydrolysis of the pyrazolephosphonic ester to the corresponding acid is described.

A Convenient One-Pot Synthesis of β -(Trifluoromethyl)allylaminophosphonic and Benzylaminophosphonic Acids

The reductive condensation of aminoalkylphosphonic acids with β -chloro- or β -ethylthio-(β -trifluoromethyl)acroleins leads to secondary (trifluoromethyl)allylaminophosphonic acids in moderate to good yields. The method appears to be useful for the preparation of benzylaminophosphonic acids.

A Convenient Synthesis of ω-(2-Aryl-4-oxothiazolidin-3-Yl)alkylphosphonic Acids via In Situ–Generated Arylideneaminoalkylphosphonic Acids

ω-(2-Aryl-4-oxothiazolidin-3-yl)alkylphosphonic acids are prepared in an easy workup procedure by the addition of methyl mercaptoacetate to in situ–generated arylideneaminoalkyl phosphonic acids.

A Convenient Synthesis of ω-[(Arylphosphonomethyl)Amino] Alkylphosphonic and Carboxylic Acids via in Situ–Generated Arylideneaminoalkyl- Phosphonic or Carboxylic Acids

ω-[(Arylphosphonomethyl)amino]alkylphosphonic and carboxylic acids are prepared in an easy work-up procedure, by addition of diethyl phosphite to in situ–generated arylideneaminoalkylphosphonic or carboxylic acids followed by hydrolysis with hydrochloric acid