R-Butyl azidoformate

Preparation. A solution of r-butyl azidoformate (1) and /-butyl carbazate (2) in pyridine is allowed to stand at room temperature for 1 week and diluted with... 

AMINO GROUP f-Amyl chloroformate. r-Butyl azidoformate. 9-Fluorenyl-methyl chloroformate. 

Cyclic amidines. Organic azides react with N-isopropylallenimine (1) to form cyclic amidines (2). In the case of r-butyl azidoformate, the product (2) can be converted into the parent N-isopropyl- -lactamimide (3). 

A -ButenoUdes, 53, 339, 411 / Butoxybi (dimetliylainino)methane, 41 t-Butyl acetoacetate, 50, 51 1-r-ButylalIene oxide, 279 r-Butyl azidoformate, 41-42 r-Butylbenzene, 362... 

Uses. r-Butyl carbazate is a key intermediate for the preparation of /-butyl azidoformate and /-butyl azidodiformate (see also Ref. 2). 

Use of (-amyl chloroformate to give the /-amyloxycarbonylamino acids has some limitations since strictly anhydrous conditions are required. Sakakibara5 has converted the reagent into the more useful (-amyl azidoformate (b.p. 81.5—82°/51—53 mm.) by reaction with anhydrous hydrazine to give (-amyl carbazate followed by reaction with sodium nitrite (compare synthesis of (-butyl azidoformate [see 1, 84]). The azidoformate reacts with amino acids in aqueous dioxane in the presence of triethylamine to give (V-r-amyloxycarbonylamino acids in yields of 70-95%. 

PEPTIDE SYNTHESIS r-Amyl chloro-formate. f-Butyl azidoformate. Diethyl methyleneraalonate. N-Ethoxycarbonyl-2-ethoxy-l,3-dihydroquinoline. Hexamethylphosphoric triamide. 1-Hydroxybenzo triazole. Triphenylphosphine—2,2 -Dipyridyl disulfide. Triphenyl phosphite. 

R = H, = Me) and (96 R = Me, R = H) is obtained by oxidative decarboxylation of the bicyclo[4.1.0]hept-3-ene-l,6-dicarboxylic acid (95) with lead tetra-acetate. The amino-acid (97), prepared from C- (o-hydroxyphenyl)glycine and t-butyl azidoformate, cyclizes to the aminobenzofuranone (98) this type of product exhibits chemiluminescence when exposed to oxygen in the presence of a base. Treatment of 2,2 -di(bromomethyl)benzil (99) with potassium t-butoxide results in an unusual intramolecular nucleophilic substitution to give the spiro-compound (100). 

Related Reagents. 7V-(r-Butoxycarbonyloxy)phthalimide N-(r-Butoxycarbonyloxy)succinimide t-Butyl Azidoformate t-Butyl Chloroformate Di-r-butyl Dicarbonate. 

Related Reagents. Allyl Chloroformate Benzyl Chlo-roformate 4-Bromobenzyl Chloroformate t-Butyl Azidoformate l-(t-Butoxycarbonyl)-lEf-benzotriazole 3-A-oxide 1 -(r-Butoxycarbonyl)imidazole 2-(t-Butoxycarbonyloxyimino)-2-phenylacetonitrile A-(t-Butoxycarbonyloxy)phthalimide A-(t-Butoxycarbonyloxy)succinimide V-(r-Butoxycarbonyl)-1,2,4-triazole Di-t-butyl Dicarbonate Ethyl Chloroformate 9-Fluorenylmethyl Chloroformate Isobutyl Chloroformate Methyl Chloroformate 2,2,2-Tribromoethyl Chloroformate 2,2,2-Trichloroethyl Chloroformate 2,2,2-Trichloro-t-butoxycarbonyl Chloride 2-(Trimethylsilyl)ethyl Chloroformate Vinyl Chloroformate. 

Related Reagents. t-Butyl Azidoformate f-Butyl Chloro-formate l-A(-(t-Butoxycarbonyl)-l//-benzotriazole 3-A-Oxide 1 -(t-Butoxycarbonyl)imidazole 2-(t-Butoxycarbonyloxyimino)-2-phenylacetonitrile A/ -(t-Butoxycarbonyloxy)phthalimide N-(7-Butoxycarbonyloxy)succinimide 1-r-Butoxycarbonyl-1,2,4-tri azole. 

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