5-azidofuran-2-carbaldehyde

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5-azido-2-furaldehyde (33 mg, 0.24 mmole) in 2 ml of ethanol was added dropwise to a solution of 5-morpholinomethyl-3-amino-2-oxazolidone (Sigma, 43 mg, 0.21 mmole) in 2.5 ml of ethanol:water (5:1) mixture, followed by 0.5 ml of 1N HCl. The reaction mix was stirred at room temperature overnight and evaporated to dryness. The residue was partitioned between 20 ml of ethyl acetate and 10 ml of 2% sodium bicarbonate. The ethyl acetate layer was kept and the aqueous layer extracted with 2×15 ml of ethyl acetate. The combined organic layer was dried over sodium sulfate, filtered and evaporated to dryness. (51 mg, 0.17 mmole, 83% yield). Silica gel TLC analysis showed a homogeneous single spot with Rf of 0.44 when developed in ethyl acetate. 1H NMR analysis of 4 revealed that it is a mixture of two isomers with the acrylonitrile moiety in cis (Z) and trans (E)-configurations (coupling constant J=11.6 and 16.5 Hz, respectively). The reaction mix evaporated to dryness The residue was partitioned between 20 ml of ethyl acetate and 10 ml of 2% sodium bicarbonate the aqueous layer extracted with 2×15 ml of ethyl acetate The combined organic layer was dried over sodium sulfate filtered evaporated to dryness a mixture of two isomers with the acrylonitrile moiety in cis (Z) and trans (E)-configurations (

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5-azido-2-furaldehyde (92 mg, 0.67 mmole) in 4 ml of ethanol was added dropwise to a solution of semicarbazide hydrochloride (75 mg, 0.67 mmole) in 10 ml of ethanol:water (5:1) mixture. The reaction mix was stirred at room temperature overnight and evaporated to dryness. The residue was dissolved in 1.2 ml of acetone and streaked on one preparative silica gel TLC plates (EM-5717-7), developed with ethyl acetate:petroleum ether (9:1). Two well-separated major bands (upper band with Rf of 0.56 and lower band with Rf of 0.20) were detected under UV lights and were separately stripped and eluted with excess of ethyl acetate. The ethyl acetate eluents were evaporated to give pale yellow residues (45 mg and 35 mg, respectively). On silica gel TLC, both residues showed identical pattern of two distinctly separated spots with Rf of 0.56 and 0.33 when the TLC was developed with ethyl acetate:petroleum ether (6:1). The TLC analysis suggested that both residues contained interconvertible cis and trans isomers and were, therefore, combined (total yield 0.48, 72%). 1H NMR analysis of 2 confirmed that it is a mixture of two isomers with the acrylonitrile moiety in cis (Z) and trans (E)-configurations (coupling constant J=11.6 and 16.5 Hz, respectively). The reaction mix evaporated to dryness The residue was dissolved in 1.2 ml of acetone eluted with excess of ethyl acetate The ethyl acetate eluents were evaporated to give pale yellow residues (45 mg and 35 mg (total yield 0.48, 72%)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5-azido-2-furaldehyde (240 mg, 1.75 millimole (mmole)) in 20 milliliters (ml) of ethanol was added dropwise over 10-20 minutes to a solution of 1-aminohydantoin hydrochloride (320 mg, 2.1 mmole) in 25 ml of ethanol:water (4:1) and the mixture was chilled in an ice bath. The reaction mixture turned into a yellow-orange suspension within thirty minutes and was gradually heated to about 60° C. to form a complete solution. The heating continued for another 24 hours after which time it was allowed to cool and evaporated to dryness. The dark residue was triturated with 4-5 portions (15 ml each) of acetonitrile to obtain a suspension which was then filtered through a filter paper. The filtrate was evaporated to dryness. The residue was dissolved in 3 ml of acetone and streaked on two preparative silica gel TLC plates (EM Science, Cat # 5717-7) and developed with ethyl acetate: petroleum ether (3:1). The fast moving major band (Rf around 0.51) detected under UV light was stripped, and the silica gel was ground to a fine powder and eluted with acetone. The acetone eluent was evaporated to give a pale yellow solid which showed a homogeneous single spot on TLC (137 mg, 0.67 mmole, 38% yield). Alternatively the crude reaction product can be purified by silica gel column chromatography and further recrystallized from 30% ethyl acetate/hexanes to give the pure desired product (mp 171-173° C.). Elemental analysis supported a molecular formula of C8H6N4O3. 0.15 EtOAc. The structure of compound 1 was established by 1H and 13C NMR analysis as shown in FIGS. 1-4. 1H NMR analysis of 1 revealed that the acrylonitrile moiety has a trans (E)-configuration (coupling constant J=16.5 Hz). MALDI-TOF mass spectral analysis confirmed structure 1 with the M+1 peak of 207.22 the mixture was chilled in an ice bath The reaction mixture turned into a yellow-orange suspension within thirty minutes to form a complete solution to cool evaporated to dryness The dark residue was triturated with 4-5 portions (15 ml each) of acetonitrile to obtain a suspension which was then filtered through a filter paper The filtrate was evaporated to dryness The residue was dissolved in 3 ml of acetone eluted with acetone The acetone eluent was evaporated to give a pale yellow solid which Alternatively the crude reaction product can be purified by silica gel column chromatography further recrystallized from 30% ethyl acetate/hexanes