| 1 | 503-00-4 | N,1,5-trimethylhexylamine | C9H21N | 143.27 | | |
| 2 | 503-01-5 | isometheptene | C9H19N | 141.256 | | 3.06g/L at 25℃ |
| 3 | 503-05-9 | malvalic acid | C18H32O2 | 280.45 | | |
| 4 | 503-06-0 | phytomonic acid | C19H36O2 | 296.49 | | |
| 5 | 503-07-1 | 11-[(2R,3S)-3-pentyloxiran-2-yl]undec-9-enoic acid | C18H32O3 | 296.44 | | |
| 6 | 503-09-3 | Epifluorohydrin | C3H5FO | 76.07 | | |
| 7 | 503-10-6 | 2-(Difluoro)oxirane 95% | C3H4F2O | 94.06 | | |
| 8 | 503-11-7 | Epoxypropionic acid | C3H5O3* | 89.07 | 196 °C (decomp) | |
| 9 | 503-12-8 | 2-Butanone, 4-(1-aziridinyl)- (7CI,8CI,9CI) | C6H11NO | 113.16 | | |
| 10 | 503-17-3 | 2-Butyne | C4H6 | 54.09 | -32 °C | Not miscible in water. |
| 11 | 503-20-8 | Fluoroacetonitrile | C2H2FN | 59.04 | -13 °C | Slightly soluble in water |
| 12 | 503-28-6 | azomethane | C2H6N2 | 58.08 | -77.9°C | |
| 13 | 503-29-7 | Azetidine | C3H7N | 57.09 | -70°C | miscible |
| 14 | 503-30-0 | Trimethylene oxide | C3H6O | 58.0791 | -97°C | Soluble in water. |
| 15 | 503-38-8 | Diphosgene | C2Cl4O2 | 197.83 | -57 °C | may decompose |
| 16 | 503-40-2 | Methionic acid | CH4O6S2 | 176.17 | 96-100° | 2458g/L(25 ºC) |
| 17 | 503-41-3 | 1,3,2,4-dioxadithiane 2,2,4,4-tetraoxide | C2H4O6S2 | 188.18 | 80°C | |
| 18 | 503-45-7 | 3,5,5-TRIMETHYLCYCLOHEXENE | C9H16 | 124.22 | | |
| 19 | 503-46-8 | 1,5,5-trimethylcyclohexene | C9H16 | 124.22 | -91.55°C (estimate) | |
| 20 | 503-47-9 | 1,3,3-trimethylcyclohexene | C9H16 | 124.22 | | |
| 21 | 503-48-0 | mevalonolactone | C6H10O3 | | | |
| 22 | 503-49-1 | 3-hydroxy-3-methylglutaric acid | C6H10O5 | 162.14 | 105-108 °C (lit.) | |
| 23 | 503-60-6 | 1-Chloro-3-methyl-2-butene | C5H9Cl | 104.58 | | Miscible with chloroform, acetone, diethyl ether and alcohol. Immiscible with water. |
| 24 | 503-64-0 | cis-Crotonic acid | C4H6O2 | | | |
| 25 | 503-64-0 | isocrotonic acid | C4H6O2 | 86.09 | 15° | |
| 26 | 503-66-2 | 3-hydroxypropionic acid | C3H6O3 | 90.08 | 16.8°C (estimate) | 270.1g/L(25 ºC) |
| 27 | 503-68-4 | diazoacetic acid | N2=CHCOOH | | | |
| 28 | 503-69-5 | N-ethylguanidine | C3H9N3 | 87.12 | | |
| 29 | 503-74-2 | Isovaleric acid | C5H10O2 | 102.13 | -29 °C (lit.) | 25 g/L (20 ºC) |
| 30 | 503-76-4 | 2-Chloro-1-nitro-propane | C3H6ClNO2 | 123.54 | | |
| 31 | 503-80-0 | CACODYLOXIDE | C4H12As2O | 225.98 | -25°C | |
| 32 | 503-81-1 | pyrocarbonic acid | C2H2O5 | 106.03 | | |
| 33 | 503-83-3 | Tetramic acid | C4H5NO2 | 99.09 | 120 °C | |
| 34 | 503-84-4 | 3,4-Dihydro-2-imino-2H-pyrrol-5-amine | C4H7N3 | 97.12 | | |
| 35 | 503-86-6 | 2-amino-1,5-dihydro-4H-imidazol-4-one | C3H5N3O | 99.09 | 208-210 °C(Solv: ethanol (64-17-5)) | |
| 36 | 503-87-7 | 2-Thiohydantoin | C3H4N2OS | 116.14 | 229-231°C (dec.)(lit.) | |
| 37 | 503-88-8 | 3,5-DIAMINO-1,2,4-TRIAZOLE | C2H5N5 | 99.09 | 202-205°C(lit.) | |
| 38 | 503-89-9 | 5-MERCAPTO-4H-[1,2,4]TRIAZOL-3-OL | C2H3N3OS | 117.13 | | |
| 39 | 503-93-5 | 2,6,6-trimethylcyclohepta-2,4-dien-1-one | C10H14O | 150.22 | 87-89 °C | |