Synthesis and antifolate evaluation of the 10-propargyl derivatives of 5-deazafolic acid, 5-deazaaminopterin, and 5-methyl-5-deazaaminopterin

Abstract

5-Deaza-10-propargylfolic acid (4), an analogue of the thymidylate synthase (TS) inhibitor 10-propargyl-5,8-dideazafolic acid (PDDF, 1), was prepared via alkylation of diethyl N-[4-(propargylamino)benzoyl]-L-glutamate (7) by 2-amino-6-(bromomethyl)-4(3H)-pyrido[2,3-d]pyrimidinone (15). Bromomethyl intermediate 15 was prepared from the corresponding hydroxymethyl precursor 14 by treatment with 48% HBr. Hydroxymethyl compound 14 was obtained by deamination of reported 2,4-diaminopyrido[2,3-d]pyrimidine-6-methanol (12a) in refluxing 1 N NaOH. Both 12a and its 5-methyl-substituted analogue 12b were converted to versatile 6-bromomethyl intermediates 13a and 13b from which important antifolates may be readily derived. Alkylation of 7 by 13a,b led to 10-propargyl-5-deazaaminopterin (5) and 5-methyl-10-propargyl-5-deazaaminopterin (6). As an inhibitor of TS from H35F/F cells, 4 gave an IC50 value showing it to be approximately 6-fold less inhibitory than PDDF (90 nM for 4 vs 14 nM for PDDF). In in vitro studies, IC50 (microM) values obtained for 4 vs L1210 and S180 of 1.50 and 2.35, respectively, were similar to those obtained for PDDF (2.61 and 1.97). Against HL60 cells, 4 was about 7-fold more cytotoxic than PDDF (IC50 values 0.72 and 5.29 microM). Inclusion of thymidine did not establish TS as the site of cytotoxic action for either 4 or PDDF in the cell lines used. In in vivo tests against L1210 in mice, 4 failed to show therapeutic effect. The 2,4-diamino compounds 5 and 6 were as potent inhibitors of DHFR from L1210 cells as MTX and 7- and 35-fold, respectively, more inhibitory than MTX toward L1210 cell growth. In mediated influx into L1210 cells, 5 and 6 were transported 2.7- and 8.5-fold, respectively, more readily than MTX. Against the EO771 mammary adenocarcinoma in mice, 6 produced greater antitumor effect than MTX. A dose of 36 mg/kg per day for 5 days caused no toxic deaths while the average tumor volume among 10 mice was reduced to 8-9% of that of the control, and 20% of the test animals were rendered tumor free.

Lipophilic Antifolates as Agents against Opportunistic Infections. 1. Agents Superior to Trimetrexate and Piritrexim against Toxoplasma gondii and Pneumocystis carinii in in Vitro Evaluations

“…The procedure for the preparation of 2,4-diamino-5-methyl-6-[(1-naphthylthio)methyl]pyrido [2,3-d]pyrimidine (13c) is representative. A mixture of K2CO3 (3.88 g, 28.1 mmol of anhydrous powder) and 1-naphthalenethiol (4.50 g, 28.1 mmol) in Me2NAc (42 mL) was stirred at 20-23 °C for 2 h before pulverized 2 (3.70 g, 8.50 mmol as 2‚1.7HBr‚0.5AcOH 27,28 ) was added. The mixture was stirred under N2 in a stoppered flask for 24 h. The mixture, now containing solid 13c, was filtered, and the solid was washed on the funnel with a little Me2NAc.…”

“…N 10 -Substituted 6-(Aminomethyl)-2,4-diamino-5-methylpyrido[2,3-d]pyrimidines 13a, 13k-u, and 14a-m. All compounds of this group except 13a and 13q were prepared by method A, reaction of bromomethyl compound 2 [25][26][27][28] with the appropriate amine. Method B, reductive amination of nitrile 4 25,29 with the appropriate amine, was used to prepare 13a and 13q.…”

“…Table 4 shows results on three 5-unsubstituted-5-deaza analogues (15a-c) and four quinazoline (5,8-dideaza) analogues (16a-d) along with side-by-side comparisons with side-chain analogues from the 5-methyl-5-deaza group. , [25][26][27][28] and 3, 27,28 the nitriles 4 25 and 5, 25 and the aldehyde 7. 27,30 2,4-Diaminoquinazoline-6-carbonitrile (6) was reported by Davoll and Johnson.…”

“…, [25][26][27][28] and 3, 27,28 the nitriles 4 25 and 5, 25 and the aldehyde 7. 27,30 2,4-Diaminoquinazoline-6-carbonitrile (6) was reported by Davoll and Johnson. 31 The reports describing the intermediates include procedures for converting them to pure dialkyl esters of classical antifolate types.…”

EO771, is it a well‐characterized cell line for mouse mammary cancer model? Limit and uncertainty

“…Thus, methotrexate, an antifolate, is tested in the mouse model of EO771 mammary cancer showing a sensitivity of this tumor to this drug. 92 This animal model is also tested for the development of a novel antifolate family as analogues of aminopterin 91,[93][94][95][96][97][98][99] whose antitumor activity is superior to methotrexate in EO771 tumor-bearing mice.…”