The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: 5-Methoxy-1H-indole-2-carbaldehyde( cas:21778-81-4 ) is researched.Name: 5-Methoxy-1H-indole-2-carbaldehyde.Hirata, Tadashi; Yamada, Yasuhiro; Matsui, Masanao published the article 《Synthetic studies on mitomycins. Synthesis of aziridinopyrrolo[1,2-a]indoles》 about this compound( cas:21778-81-4 ) in Tetrahedron Letters. Keywords: indoles; indoles pyrrolo; pyrroloindoles; mitomycins. Let’s learn more about this compound (cas:21778-81-4).
Conversion of the nitro compounds 2,4,5-Me(R1O)R2C6H2NO2 (R1, R2 = Me, H; Me, Me; PhCH2O, H; PhCH2O, Me) by a modified Reissert indole synthesis gave the esters I (R3 = CO2Et), m. 155-6, – , – , 141-2°, resp., reduced by LiAlH4 to the alcs. I (R3 = CH2OH), m. 83.5-5.0, 139-40, 103-4, 100-3°, resp., oxidized in turn by KMnO4 in Me2CO with poor yields (10-20%) or with yields up to 90% by CrO3-C5H5N of the corresponding aldehydes I (R3 = CHO), m. 136-7, 172-3, 178-9, 172-5°, resp. The aldehydes treated with NaH and H2C:CHPPh3Br in tetrahydrofuran (THF) gave 80-8% yields of 9H-pyrrolo[1,2-a]indoles (II) (R1, R2 = Me, H; PhCH2O, H; PhCH2O, Me), m. 80-1, 88-9, 88-9°, resp., with structures supported by uv and N.M.R. spectra. Acylation of II with KOCMe3 and Me2CO3 afforded 60-80% 3H-pyrrolo-[1,2-a]indoles (III) (R4 = OMe), m. 121-3, 122-3, 139-41°, resp. Similarly acylation with HCO2Et gave III (R4 = H; R1, R2 = Me, H; PhCH2O, Me), m. 135-41 (decomposition), and 138-42°, with structures supported by ir, uv, and N.M.R. spectra. Functionalization of the vinylic double bond of III for attachment of the aziridine moiety was achieved by iodine-azide addition giving 74-5% yields of iodo-azides (IV, R1, R2 = Me, H; PhCH2O, Me), m. 93.8-4.5, and 171-9°, ir, uv, and N.M.R. spectral data given. Catalytic hydrogenation of IV over Pd-C in MeOH containing HCl gave 60-90% yields of the corresponding iodo-amine hydrochlorides, m. >300, >300°, yielding the expected iodoamines, m. indefinite, 135-41° (decomposition), resp., ir bands (Nujol) given. Protection of the amine group with ClCO2Me furnished the iodo carbamates (V) (R5 = H; R1, R2 = Me, H; PhCH2O, Me) (VI, VII), m. 160-2 and 183-4°, resp. Cyclization with NaOMe in (MeOCH2)2 or THF gave VIII (R5 = H; R1 = Me, R2 = H), m. 210.5-14.5°, with structure confirmed by spectroscopic data, and VIII (R5 = H, R1 = PhCH2O, R2 = Me), m. 219.5-21.5°. Nitration of VI and VII gave the 8-nitro derivatives V (R5 = NO2, R1, R2 = Me, H; PhCH2O, Me), m. indefinite and 192-9°, resp. The location of the NO2 group was elucidated by N.M.R. spectral anal. The ring closure of the 8-nitro derivatives similarly gave the corresponding aziridines, VIII (R5 = NO2; R1, R2 = Me, H; PhCH2O, Me), m. 242-6, and 232-3.5°.
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Reference:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem