Nitrophenyl Experimental Procedure

In this section we provide experimental procedures for the synthesis of various 2-nitrophenyl-containing amino acid derivatives glutamic acid derivative 109 230 (Scheme 28), glycine derivative 112 230 and aspartic acid derivative 114 230 (Scheme 29), Fmoc-protected tyrosine derivative 119 234 (Scheme 30), and glycine derivatives 120 235 and 122 232 (Scheme 31). 

Wang resin bound 4-nitrophenyl carbonate is a convenient intermediate for the attachment of amines to polystyrene as carbamates (see Experimental Procedure 14.2). Aliphatic amines [82-87], ammonia [88], and amino acids [89] react exothermically with this support, whereas anilines generally require catalysis and/or long reaction times (Entry 3, Table 14.7). For the immobilization of anilines as carbamates, Wang resin derived chloroformate [90-92] generally leads to better results than resin-bound 4-nitrophenyl carbonates. Amidines also react with polystyrene-bound 4-nitrophenyl carbonates to yield /V-alkoxycarbonyl amidines (Section 3.9 [93-95]). Support-bound alkoxycarbonyl hydrazines can be prepared by treating polystyrene-bound phenyl carbonates with hydrazine [96-98]. 

UV spectrum, 170 1-dibromoethane, 568 erythro-2,3 -dibromo -3 - (4 -nitrophenyl)propiophenone experimental procedure, 520-523 IR spectrum, 522 physical properties, 528 purification and characterization, 521-523... 

The chloramine derivatives (ArS02NClNa) of a variety of other aryl-sulfonamides (Ar = phenyl, o-tolyl, p-chlorophenyl,/>-nitrophenyl, and o-carboalkoxyphenyl) have been used successfully in these catalytic oxy-aminations. Since only chloramine-T (Ar = p-tolyl) and chloramine-B (Ar = phenyl) are commercially available, we have developed a convenient procedure for generating the chloramines in situ for use in the modification involving phase-transfer catalysis. One simply stirs a suspension of the arylsulfonamide with an equivalent of sodium hypochlorite (Clorox) until a homogeneous solution is obtained. When this solution is used in the PTC method (see Ref. 2 for experimental details), the yields of oxyaminated product are comparable with those obtained with isolated chloramine salts. 

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