The reaction of 4-amino-1H-imidazole-5-carbonitrile with trimethyl orthopentanoate in hot DMF gives methyl N-(5-cyano-1H-imidazol-4-yl)pentanoimidate , which is then cyclized with benzoic hydrazide in hot DMF to yield the target triazolo-purine derivative.

1. Introduction of Trimethyl orthovalerate

 Trimethyl orthovalerate , with its CAS NO 13820-09-2, is a kind of colorless liquid. It has the synonyms of Orthovalericacid, trimethyl ester (6CI,7CI,8CI);1,1,1-Trimethoxypentane and Trimethylorthopentanoate. Trimethyl orthovalerate should be stored in shady and cool warehouse and mainly used as Pharmaceutical Intermediates.

2. Properties of Trimethyl orthovalerate

(1) Molecular Weight: 162.23g/mol (2) Mol File: 13820-09-2.mol
(3) EINECS: 237-496-5 (4) Boiling point: 165 °C at 760 mmHg (5) Storage Temperature: Flammables area
(6) Flash Point: 41.7 °C  (7) Density: 0.902 g/cm3 (8) Refractive index: 1.408-1.41
(9) Sensitive: Moisture Sensitive (10) Index of Refraction: 1.407  (11) Molar Refractivity: 44.31 cm3
(12) Molar Volume: 179.7 cm3 (13) Surface Tension: 25.6 dyne/cm (14) Enthalpy of Vaporization: 38.5 kJ/mol
(15) Vapour Pressure: 2.51 mmHg at 25°C (16) XLogP3-AA: 1.7 (17) H-Bond Acceptor: 3

3. Structure descriptors of Trimethyl orthovalerate

Canonical SMILES: CCCCC(OC)(OC)OC
InChI: InChI=1S/C8H18O3/c1-5-6-7-8(9-2,10-3)11-4/h5-7H2,1-4H3
InChIKey: XUXVVQKJULMMKX-UHFFFAOYSA-N

4. Safety information of Trimethyl orthovalerate

Hazard Codes: , 
The Risk Statements information of Trimethyl Orthovalerate:
10: Flammable
36/37/38: Irritating to eyes, respiratory system and skin
36/38: Irritating to eyes and skin
The Safety Statements information of Trimethyl Orthovalerate:
16: Keep away from sources of ignition - No smoking
26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
36: Wear suitable protective clothing
37/39: Wear suitable gloves and eye/face protection
RIDADR: 1993
HazardClass: 3
PackingGroup: III