Guido Steffan
40Patents
5h-index
57Co-inventors
72Inventor score
Filing activity: Jan 11, 1978 → Feb 7, 2002
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5681957A | Process for the preparation of substituted 2-fluoro-pyrimidines | Chemistry; Metallurgy | 12 | Expired |
| US6355827B1 | Process for preparing 2-cyanoindan-1-ones | Chemistry; Metallurgy | 10 | Expired |
| US5677453A | Process for the preparation of 4,6-dichloropyrimidines | Chemistry; Metallurgy | 8 | Expired |
| US4217209A | Process for removing heavy metal sulphides from aqueous systems | Emerging Cross-Sectional Technologies | 6 | Expired |
| US6015771A | Thermally-responsive record material | Performing Operations; Transporting | 5 | Expired |
| US6455725B1 | Substituted cinnamic acids and cinnamic acid esters | Chemistry; Metallurgy | 5 | Expired |
| US4325889A | Process for the preparation of 1-amino-8-naphthol-3,6-disulphonic acid (H-acid) | General | 4 | Expired |
| US5719285A | Process for the preparation of polychloropyrimidines | Chemistry; Metallurgy | 4 | Expired |
| US4760209A | Process for preparing 3,5-dichloro-.alpha.-methylstyrene | Chemistry; Metallurgy | 2 | Expired |
| US6294502A | Thermally-responsive record material | Performing Operations; Transporting | 2 | Expired |
| US5283338A | Process for the preparation of 2-chloropyridines | Chemistry; Metallurgy | 2 | Expired |
| US6441171B1 | Method for the production of 4,6-dichloropyrimidine with the aid of phosgene | Chemistry; Metallurgy | 2 | Expired |
| US6296788A | Process for the preparation of Grignard reagents and novel Grignard reagents | Chemistry; Metallurgy | 2 | Expired |
| US5900509A | Process for the preparation of p-haloalkoxyanilines | Chemistry; Metallurgy | 2 | Expired |
| US4341720A | Process for the preparation of oxalyl chloride | Chemistry; Metallurgy | 2 | Expired |
| US4163752A | Process for the preparation of aminonaphthalenesulphonic acids | General | 1 | Expired |
| US6184417A | Method for preparing acetophenones with a fluoralkyl-substituted aromatic nucleus | Chemistry; Metallurgy | 1 | Expired |
| US4180521A | Process for the preparation of naphthalene-1,3,6-trisulphonic acid | Chemistry; Metallurgy | 1 | Expired |
| US4267346A | Process for the preparation of 1,2,4-triazole | Chemistry; Metallurgy | 1 | Expired |
| US5679826A | Process for the preparation of 2-chloroacrylonitrile | Chemistry; Metallurgy | 1 | Expired |
| US5464875A | Process for preparing weakly-basic anion exchangers and reagents suitable for this purpose | Chemistry; Metallurgy | 1 | Expired |
| US5693831A | (2,3-dihydro-5-benzofuranyl)-acetonitrile | Chemistry; Metallurgy | 1 | Expired |
| US6162917A | Method of preparing 4,5,6-trichloro- and 2,4,5,6-tetrachloropyrimidine | Chemistry; Metallurgy | 1 | Expired |
| US4764621A | Preparation of 2-chlorobenzthiazole | Chemistry; Metallurgy | 1 | Expired |
| US6433228B1 | Process for preparing 2-halogenated indan-1-ones | Chemistry; Metallurgy | 1 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.