Org. Synth. 1984, 62, 187
DOI: 10.15227/orgsyn.062.0187
DIPHENYL PHOSPHORAZIDATE
[Phosphorazidic acid, diphenyl ester]
Submitted by Takayuki Shioiri
1 and Shun-ichi Yamada
2.
Checked by Christina Bodurow and M. F. Semmelhack.
1. Procedure
A mixture of 56.8 g (0.21 mol) of diphenyl phosphorochloridate (Note 1), 16.3 g (0.25 mol) of sodium azide, and 300 mL of anhydrous acetone (Note 2) in a 500-mL round-bottomed flask fitted with a calcium chloride tube is stirred at 20–25°C for 21 hr. The lachrymatory mixture is filtered in a hood, and the filtrate is concentrated under reduced pressure. The residue is distilled through a short Vigreux column (Note 3). The yield of diphenyl phosphorazidate, bp 134–136°C (0.2 mm), is 49–52 g (84–89%) (Note 4).
2. Notes
1.
Diphenyl phosphorochloridate (diphenyl chlorophosphate), from Aldrich Chemical Company, Inc., was used after purification by distillation at 165–168°C (5 mm).
2.
Commercial
acetone was dried over anhydrous
potassium carbonate and distilled.
3.
The bath temperature should be kept below 200°C to minimize decomposition of
diphenyl phosphorazidate.
3
4.
Diphenyl phosphorazidate is a colorless nonexplosive oil that can be kept for a long time without decomposition if it is protected against light
3 and moisture.
3. Discussion
The procedure described is essentially that of Shioiri and Yamada.
4 Diphenyl phosphorazidate is a useful and versatile reagent in organic synthesis.
5 6 It has been used for racemization-free peptide syntheses,
4,7,8 thiol ester synthesis,
9 a modified Curtius reaction,
7,10,11 C-acylation of active methylene compounds,
12 esterification of an α-substituted carboxylic acid,
13 formation of diketopiperazines,
14 an alkyl azide synthesis,
15 phosphorylation of alcohols and amines,
16 and polymerization of amino acids and peptides.
17 Furthermore,
diphenyl phosphorazidate acts as a nitrene source
3 and as a 1,3-dipole.
18,19 An example of the ring contraction of cyclic ketones to form cycloalkanecarboxylic acids is presented on page 135 in this volume.
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
Diphenyl phosphorochloridate (diphenyl chlorophosphate)
potassium carbonate (584-08-7)
acetone (67-64-1)
sodium azide (26628-22-8)
diphenyl phosphorochloridate (2524-64-3)
Diphenyl phosphorazidate,
Phosphorazidic acid, diphenyl ester (26386-88-9)
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