Temozolomide Acid

Preparation of TMZ acid (EP0252682) TMZ (2.577mmol, 0.5g) was mixed with concentrated sulfuric acid (4ml) with agitation. Sodium nitrite (9.4mmol, 0.65g) was dissolved in 2.6ml of water and then dropped into aforementioned mixture on an ice bath at temperature of below 15°C, to stir at room temperature overnight. The resulting mixture continued to be added with 10g of ice and cool for 1 hour in ice-bath. The solid product was colleted by filtration, and dried in vacuo to give 0.493g of TMZ acid. The yield was 98.6percent.TMZ-carboxylic acid (shown as compound 1 in FIG. 1) was prepared following a previously described procedure. See, e.g., Arrowsmith, J.; Jennings, S. A.; Langnel, D. A. F.; Wheelhouse, R T.; Stevens, M. F. G. Antitumour Imidazotetrazines. Part 39. Synthesis of Bis(Imidazotetrazines) with Saturated Space Groups. J. Chem. Soc., Perkin Trans. 2000, 1, 4432-4438. In a round bottom flask charged with a stir bar and fitted with an addition funnel, TMZ (2.29 grams, 11.8 millimoles) was dissolved in concentrated HOf the following method of formula 6 through to 3-methyl-4-oxo -3, 4- the D draw already trillion which is [5, 1-d] [1, 2, 3, 5] - 8-tetrazine neel claw id carbonate have been prepared. 3-methyl-4-oxo -3, 4 - [5, 1-d] [1, 2, 3, 5] the D draw already trillion which isthe car diplopia it buys -8-tetrazine (94 mg, 0.482 mmol) of thiosalicylic thionil chloride (SOCl 2, 1 ml) senses a rotation velocity of the disk to, dimethylformamide (1 drop) for inserting and removing adaptation stirring time 1 in 100 C. 1 process has been completed, reactants marked on the specific a high temperature to the normal temperature after the vacuum drying/concentrate without further refinement the ground terminal of to next reactorPreparation of TMZ acid (EP0252682) TMZ (2.577mmol, 0.5g) was mixed with concentrated sulfuric acid (4ml) with agitation. Sodium nitrite (9.4mmol, 0.65g) was dissolved in 2.6ml of water and then dropped into aforementioned mixture on an ice bath at temperature of below 15C, to stir at room temperature overnight. The resulting mixture continued to be added with 10g of ice and cool for 1 hour in ice-bath. The solid product was colleted by filtration, and dried in vacuo to give 0.493g of TMZ acid. The yield was 98.6%.TMZ-carboxylic acid (shown as compound 1 in FIG. 1) was prepared following a previously described procedure. See, e.g., Arrowsmith, J.; Jennings, S. A.; Langnel, D. A. F.; Wheelhouse, R T.; Stevens, M. F. G. Antitumour Imidazotetrazines. Part 39. Synthesis of Bis(Imidazotetrazines) with Saturated Space Groups. J. Chem. Soc., Perkin Trans. 2000, 1, 4432-4438. In a round bottom flask charged with a stir bar and fitted with an addition funnel, TMZ (2.29 grams, 11.8 millimoles) was dissolved in concentrated H2504 (23.6 milliliters), and the resulting yellow solution was cooled at 0 C. under nitrogen. A solution of sodium nitrite (2.51 grams, 36.4 millimoles) in water (23.6 milliliters) was then added drop-wise over 45 minutes, noting the evolution of a brown gas during addition. The mixture was allowed to warm to room temperature and was stirred under nitrogen, protected from light. After stirring for 17 hours, the solution was cooled at 0 C., and the reaction was quenched with ice (61.26 grams). Further stirring at 0 C. resulted in the precipitation of 1 as a fine white solid, which was isolated by vacuum filtration, washed with cold water, and dried under high vacuum to afford 1 in 75% yield. 1H-NMR (500 MHz, DMSO-d6, delta, ppm): 3.88 (s, 3H), 8.82 (s, 1H), 13.33 (br, 1H). 13C-NMR (125 MHz, DMSO-d6, delta, ppm): 36.32, 127.78, 129.09, 136.48, 139.10, 161.85. HRMS-EI (m/z): [M]+ calculated for C6H5N5O3: 195.0392, found: 195.0395.As shown in FIG. 1a, the 5mg TMZ dissolved in 47ml of concentrated sulfuric acid and the resulting yellow solution was cooled to 0 under nitrogen, was added dropwise 47ml aqueous solution of sodium nitrite (4.02g, 72.8mmol) in.The mixture was allowed to warm to room temperature while protected from light After stirring 24h, the mixture was cooled to 0 and quenched with 122g of ice.Further stirred at 0 a white solid precipitate was isolated by vacuum filtration.Washed with cold water, and dried in vacuo TMZ-COOH.